Dr Benedikt Riedl, Mjur (Oxford), postdoctoral researcher and academic assistant at the Chair of Public Law and Legal Philosophy (Prof Dr Peter M. Huber, former Justice of the Federal Constitutional Court and former Minister of the Interior) at LMU Munich.
Photo credit: Nicola
Quarz, via Wikimedia
Commons
Ultra Vires Review as a Legal Concept
within EU Law
When disputes arise over the boundaries of EU
authority, a deeper constitutional tension surfaces: Quis iudicabit – who gets
to draw the final line? This question shapes one of the central controversies
in EU law: the legitimacy and limits of ultra vires review.
The first
part of the blogpost argued that ultra vires review is not an isolated or
purely national phenomenon, but a widespread and constitutionally grounded
legal practice across the EU. This second part goes further, arguing that ultra
vires review is not only compatible with Union law but embedded within it.
Anchored in the principle of conferral (Article 5(2) TEU) and safeguarded by
Article 4(2) TEU, the authority of national constitutional courts to assess
whether EU institutions have acted beyond their powers forms an integral part
of the EU’s composite legal order. Rather than threatening the primacy of EU
law, ultra vires review reinforces its democratic legitimacy by ensuring that
integration remains bound by constitutional limits. To that end, this blogpost
also sets out four cumulative steps for invoking ultra vires review as a
concept of EU law – proposing a structured, treaty-compatible procedure
designed to enhance mutual trust, legal certainty, and institutional balance
across the European constitutional landscape.
Doctrinal classification of ultra vires
review as a general principle of Union law
1 The authority of
Member States’ constitutional courts to declare acts of EU institutions ultra
vires – and, as a result, to deny them legal effect within the national legal
system – constitutes a general legal principle of EU law. This conclusion is
grounded in the EU’s foundations in public international law and supported by
comparative constitutional analysis. The invalidation of legal acts that
manifestly exceed EU competences follows from a systematic interpretation of
the fundamental principles underlying EU law. Moreover, the EU Treaties contain
no provision that prohibits Member States from conducting ultra vires reviews. Accordingly,
ultra vires review should be understood as an established legal concept within
the framework of EU law.
Principles of International Law: A Derived
Legal System
2 The CJEU asserts
the absolute autonomy of EU law without offering a clear normative foundation
in the treaties or justification under the law as it stands (de lege lata). In reality,
however, it is the national constitutions that provide both the foundational
basis and the essential point of reference for EU law. This becomes evident
through an analysis of the EU treaties and their historical development. The
treaty text, treaty practice, and drafting history all consistently affirm this
perspective. The treaty text includes numerous provisions that explicitly recognize
the existence and evolution of the Union’s legal order as deriving from the
will of the Member States. Treaty practice further reinforces this: several
treaty amendments have failed due to the Member States’ refusal to ratify them.
This shows that the EU legal order has never been truly autonomous; it has
always been contingent on the voluntary political decisions of the Member
States. The EU is based on the collective will of its Member States under
international law. Its legal order draws its validity and legitimacy from the national
acts of assent and the authorisation granted by Member States for the
application of EU law. Only on this foundation can the EU legal order maintain the
level of democratic legitimacy necessary for a direct connection to the
citizens of the Member States.
3 Given the EU’s
interconnected legal structure, the position adopted by the Member States is
persuasive. It accurately reflects the constitutional reality of Europe: a
union of open constitutional states committed – albeit sometimes cautiously –
to cooperative judicial solutions. The constitutions of the Member States serve
as both the legal foundation and the primary reference point for EU law. As a
result, EU law and national constitutional law form a single, integrated legal
system. Within this framework, ensuring effective legal protection is a shared
responsibility – carried out through a cooperative network of constitutional
courts, referred to as the Verfassungsgerichtsverbund in German legal
scholarship.
4 Absolute primacy
of EU law or the notion of an autonomous legal order cannot be established
through subsequent practice or customary law for several reasons. First, the
failure of the Constitutional Treaty clearly demonstrates a lack of political consensus
among the Member States to codify a clause providing for the EU law’s absolute
primacy. Second, due to the interconnected and multi-layered nature of EU law,
Member States cannot be reduced to their governments alone. While governments
may ratify treaty amendments without reservations, this does not take into
account the constitutional courts, which act as additional constitutional
authorities. Their jurisprudence must be taken into consideration in areas
where legal orders overlap – and these courts have consistently rejected the
idea of absolute primacy of EU law. Finally, customary law cannot emerge contra
legem – that is, in contradiction to the express provisions of the EU treaties.
As will become clear in the following, this may include Articles 2 TEU, 4(2)
TEU, 5(2) TEU, 10 TEU, and 19 TEU.
5 Furthermore, the CJEU’s
concept of autonomy is incompatible with its own jurisprudence. In Van Gend
& Loos and Costa v. E.N.E.L., the CJEU explicitly grounded the primacy of
EU law on the principle of conferral. Recently, however, the Court contradicted
itself: It has invoked the unconditional ratification of amending treaties to
support its position while simultaneously rejecting the justification of
primacy based on a delegation of powers. The demands for uniformity and
effectiveness of EU law do not justify arbitrary interference with Member
States' constitutional identities. In summary, the concept of autonomy lacks
both factual support and legal justification.
6 EU law does not
derive its legitimacy from a constitutional act or any other foundational norm;
instead, its legitimacy is functional rather than constitutional or supra-legal
in nature. This limited and contingent basis for legitimacy distinguishes EU
law from the constitutional systems of the Member States. As a result, EU law
can only evolve into a genuinely autonomous legal order through a process of
constitutionalisation by the European peoples – a process that has not yet
taken place. The functional and pragmatic rationale underlying EU law, which is
focused on practical effectiveness, neither establishes genuine autonomy nor
justifies claims to absolute institutional or substantive authority.
7 Since EU law is
not autonomous but derived from – and closely linked to – the constitutions and
democratic will of the Member States, ultra vires review aligns with the
foundational principles of EU law. Due to EU law’s character as a derived legal
order, national courts may, in certain cases, review the application of
secondary EU law and assess its validity within their domestic legal systems –
especially when EU institutions exceed the competences conferred upon them by
the Member States.
Comparative Constitutional Analysis: The
Invalidation of EU Measures Exceeding Conferred Powers as a Core Legal
Principle in Member State Constitutions
8 Comparative
constitutional analysis demonstrates that ultra vires review is the procedural
and institutional expression of a general constitutional principle: EU legal
acts that exceed the competences conferred through the national parliaments’ acts
of assent are not valid within the Member States. Here, national constitutional
courts step in to conduct an ultra vires review when the CJEU fails to assess
the limits of EU competences. By safeguarding the division of powers between
the EU and Member States, these reviews uphold a fundamental constitutional
principle. While national constitutions refer to this principle in different
terms – such as sovereignty, the republican form of government, democracy, or
popular sovereignty – they all serve the same functional purpose: to ensure the
democratic legitimacy and internal coherence of EU measures within the national
legal order.
9 From a formal
standpoint, ultra vires review implements the principle of limited conferred
powers in a procedural way. It builds on the widely accepted legal principle that
actions beyond conferred competences are prohibited. The EU’s lack of competence-competence
(Kompetenz-Kompetenz) – i.e. its inability to unilaterally define the scope of
its own powers – is explicitly affirmed in Article 5(2) TEU. Since competences
are transferred through acts of the Member States, all constitutional courts recognizing
ultra vires review consider procedural enforcement of these limits a
constitutional necessity. This ensures that the substantive principle of
limited conferred powers is not left without procedural safeguards. This logic
is also persuasive within the context of the European composite legal order:
while no constitutional court disputes the CJEU’s authority to interpret the
limits of EU competences, all reject the notion that the CJEU can unilaterally
determine the boundaries of its own jurisdiction. The domestic legal
consequences of such determinations are governed by each Member State’s acts of
assent. In any event, the CJEU has not been granted the ultimate authority to
define or transform the constitutional orders of the Member States.
10 In substantive
terms, ultra vires review serves to protect both popular and state sovereignty.
Its justification lies in the idea that when EU institutions overstep their
competences, they undermine democratic accountability and violate the right of
citizens in the Member States to self-determination. Political
self-determination is understood both individually and collectively, as tied to
the state. The core issue remains the same: if EU institutions act beyond their
conferred powers, those actions lack a proper legal basis and, consequently,
democratic legitimacy. These acts intrude upon the regulatory autonomy of the
Member States and the democratic self-determination of their citizens.
Ultimately, it is up to the sovereign – the citizens of the Member States – to
decide whether and to what extent EU law applies within their national legal
systems. This is determined by the respective parliaments through their acts of
assent, which define the scope of EU law within the national constitutional
framework via the so-called “integration programme.” Under a compelling
interpretation, ultra vires review thus acts as a procedural safeguard of the
European peoples’ right to self-determination ensuring the democratic
responsiveness of EU law to every citizen. At the same time, it enables the
very transfer of sovereign powers, without which the democratic principle
itself could be placed at risk.
Article 5(2) TEU: The Composite Structure
and Constitutional Anchoring of EU Law
11 EU law and
national constitutional law form an integrated legal system. The European Union
is a union of constitutional states open to legal integration and cooperation.
European secondary law and national law are structurally interconnected through
the framework of European primary law. Accordingly, the constitutions of the
Member States contribute to an interlinked constitutional order. Legal
questions that arise at the intersection of different legal systems must
therefore be assessed in light of the mutual interdependence between national
law and EU law. The principle of conferral has both a European and a national
dimension and is therefore of dual nature. At the European level, it is
enshrined in Article 5(2) TEU; at the national level, it is implemented through
constitutional opening clauses and acts of assent authorising the application
of EU law. In EU law, this principle reflects the limited transfer of sovereign
powers from the Member States to the Union. As such, it is not solely a
principle of EU law; it also incorporates into primary law the constitutional
reality of the Member States and the EU’s dependence on their sovereign
decisions under international law. Like Article 4(2) TEU, it expresses both the
constitutional origin and the composite nature of the Union’s authority.
12 Moreover, the CJEU
itself is directly bound by the principle of conferral, as evidenced by Article
19 TEU. The limited scope of its judicial mandate – in both competence and
legitimacy – is clearly articulated in the EU Treaties: Article 19(1), first
subparagraph, sentence 2 TEU states that the CJEU ensures the observance of the
law "in the interpretation and application of the Treaties," while Article
19(1), second subparagraph TEU limits effective legal protection to "the fields
covered by Union law." In this way, the European judicial system reflects
the EU’s compound structure. The interconnection of judicial systems operates
in both directions: the CJEU is integrated into the judicial framework of the
Member States, and national courts are functionally embedded in the enforcement
of Union law. Legal protection within this network of constitutional courts is
established in the EU Treaties as a shared responsibility between the CJEU and
the constitutional courts of the Member States.
13 The involvement
of national constitutional courts in the ultra vires procedure is the
procedural and institutional consequence of the dual nature of the principle of
conferral. Since questions of competence arise in both the EU sphere
(interpretation of EU law) and the Member State sphere (interpretation of the
integration programme and constitutional opening clauses), resolving such
conflicts requires cooperation between the CJEU and national constitutional
courts in accordance with Article 19 TEU. The procedural treatment of ultra
vires conflicts thus reflects the multidimensional nature of the primacy of EU
law and must therefore be addressed institutionally at both levels – by the CJEU
as well as the national constitutional courts.
14 The transfer of
competences to the EU takes place through national legal acts in accordance
with constitutionally prescribed procedures and therefore logically precedes any
consideration of the primacy of EU law. These constitutional parameters –
reflected in the EU Treaties, particularly in Article 5(2) and Article 19 TEU –
form the basis for the residual competence of national constitutional courts to
review the boundaries of conferred powers. In principle, Member States have
entrusted the CJEU with this competence of review, and national constitutional
courts can rely on the CJEU to fulfil it in accordance with Article 19(1),
subparagraph 2 TEU. However, if the CJEU fails to adequately exercise its control
function, national constitutional courts retain a fallback responsibility to
safeguard the proper delineation and exercise of competences. Absent this
fallback mechanism, they would ultimately be stripped of their original role of
protecting the national constitution and identity, reducing their function to a
mere absurdity. The ultra vires procedure – while primarily vested in the CJEU
and exercisable only as a last resort by national constitutional courts –
derives directly from the principle of conferral embedded in the acquis
communautaire of EU law.
Democratic principles and the context of
legitimacy in the European Union
15 The involvement
of national constitutional courts in ultra vires procedures can be justified
not only by the principle of conferral but also by invoking Article 2 TEU
and the democratic principles underpinning the European Union. This argument is
based on the role of national parliaments and the principle of conferred
powers. It underscores the fact that when EU institutions act beyond their
competences, the essential link of democratic legitimacy between the Union's
authority and the citizens of the Member States is compromised. In such instances,
the control conducted by constitutional courts serves as a necessary corrective
to uphold the democratic foundation of the EU.
16 The European
Union derives its democratic legitimacy through two channels: the European
Parliament (Article 10(2) subpara. 1 and Article 14 TEU) and national
parliaments (Article 10(2) subpara. 2 and Article 12 TEU). The EU's
well-documented democratic deficit – characterised by issues such as unequal
voting rights, an insulated executive branch, and limited public engagement –
is mitigated by the Member States’ respective democracies, particularly through
their national parliaments. These parliaments play a crucial role in
legitimizing the EU. A distinction can be drawn between the European
Parliament’s direct exercise of democratic functions and the national
parliaments’ broader responsibility for overseeing the integration process. If EU
institutions overstep their competences and thereby undermine the authority of
national parliaments, one of the foundational pillars of European democracy is
weakened, resulting in a decline of democratic legitimacy for the EU as a whole.
17 The principle of
conferral is closely tied to the democratic values enshrined in Article 2 TEU.
A core element of the EU’s democratic framework is the concept of legitimacy
based on competences. As a derived legal order, the EU is legitimised through
the competences conferred upon it. The democratic principles of the Union go
beyond a purely formal notion of authority based on the transmission of the
citizens’ will into institutional power. Instead, they require a substantive,
effective realisation of that will – specifically, the guarantee of genuine
popular sovereignty. Grounded in the principle of conferral and reinforced by
Article 4(2) TEU, the EU legal order itself respects the legislative authority
of national parliaments and the democratic will of the citizens in the Member
States.
18 Ultra vires
review plays a pivotal role in preserving democratic legitimacy within the
European Union – specifically, the legitimacy that flows through the
parliaments of the Member States. Its primary function is to uphold democracy
within the European network of states, constitutions, legislative bodies,
administrations, and judicial systems. By monitoring the limits of conferred
competences, ultra vires review serves as a safeguard or compensatory mechanism
critical for upholding democracy – in other words, it is democracy-specific. This
is particularly significant for preserving individuals’ rights to
self-determination. In the context of European supranational integration, ultra
vires review exposes the diffusion of political responsibility, thereby
promoting greater transparency and accountability in decision-making by EU
institutions.
19 In principle,
the CJEU is responsible for ensuring compliance with the division of
competences within the EU. Even if a decision is incorrect, a competence review
has still taken place. However, if a decision by the CJEU no longer meets the
required methodological standards, the review is reduced to a merely formal
check. In such cases, the substantive core of the European understanding of
legitimacy is no longer upheld. At the same time, Article 2 in conjunction with
Article 5(1) and (2) TEU allows for a decentralised review of competences by
constitutional courts in the Member States. These courts supervise the
boundaries of the EU’s derived authority to safeguard the substantive
foundations of democracy – namely, meaningful parliamentary influence and
effective popular sovereignty.
Rule of Law and Separation of Powers in the
Judicial System
20 Several factors
have contributed to the CJEU's de facto position as an almost unchecked
authority within the EU legal order. These include the constitutionalisation of
EU law, its limited embeddedness in a European public sphere, the CJEU’s dual
role as both a constitutional and specialised court, the absence of
sector-specific competence rules, and its broad, teleological approach to
interpretation. This situation is further exacerbated by the fact that the CJEU
increasingly positions itself not as the “guardian” of the EU legal order, but
as the “engine of integration.” In this role, it applies double standards in
its judicial review of competences: When reviewing infringements of EU law by
Member States, the CJEU exercises strict scrutiny. By contrast, in cases where
EU institutions themselves exceed their competences, it displays significant
leniency. To date, the CJEU has found an overreach of competences by EU
institutions only in four cases. In some judgments, the level of scrutiny
applied to EU bodies is so minimal that it amounts to a superficial or merely
evidentiary review. This approach conflicts with the EU’s commitment to
representative democracy under Article 10(1) TEU, the right to effective legal
protection, and the obligation to examine facts under Article 47 CFR and
Articles 6 and 13 ECHR. This jurisprudence has contributed to a gradual shift
of competences toward the EU without any formal treaty amendments. As a result,
it undermines the legal basis of institutional action and weakens formal
legitimacy within the EU. The expanding scope of EU competences, without a
corresponding increase in democratic legitimacy, also diminishes the Union’s substantive
legitimacy.
21 Within the
European judicial system, the CJEU regards itself as the highest authority,
positioned above the national constitutional courts. While the Court has
repeatedly acknowledged both the EU’s lack of statehood and the limited scope
of its competences, it nonetheless expands its jurisdiction into core areas of
national constitutional law – thereby infringing upon the jurisdictional authority
of the Member States' highest courts. This leads to a growing disconnect
between the principles of direct applicability and primacy of EU law, on the
one hand, and the foundational principle of conferral, on the other. It also
results in EU law penetrating the most protected spheres of national
constitutional orders. In doing so, the CJEU disregards the jurisprudence of
national constitutional courts – even in areas where EU law and national
constitutional law are closely interlinked.
22 In this context,
ultra vires review plays a key role in safeguarding the separation of powers
and establishing checks and balances within the European network of
constitutional courts. A judicial equilibrium between the EU and the national
level can be maintained through disagreement as well as ongoing dialogue.
Clearly defining the limits of competence enhances legal certainty and builds
trust in future steps toward integration. Moreover, ultra vires review offsets
the CJEU’s limited capacity for internal control within the European
constitutional system – a limitation resulting from the absence of a judicial
hierarchy, insufficient public scrutiny, lack of opposition, and constrained
legislative oversight. At the same time, it acts as a safeguard, protecting
national constitutional systems from an unchecked assertion of EU authority.
Article 4(2) TEU: Protecting Constitutional
Identity as a Systemic Exception to the CJEU’s Exclusive Authority to
Invalidate EU Acts
23 Article 4(2) TEU
directly reflects the considerations outlined above, which stem from the EU’s
compound constitutional structure. This provision can be understood as
implicitly acknowledging that, in strictly limited and extraordinary
situations, Member States may invoke ultra vires review. As will be shown
below, such an interpretation does not conflict with the general principles of
EU law, but rather takes into account the structural diversity and
constitutional identity of the Member States. Article 4(2) TEU may therefore be
read as establishing a system-inherent exception to both the primacy of EU law
and the CJEU’s exclusive jurisdiction to invalidate Union acts. In rare cases,
this exception could be asserted procedurally through an ultra vires review,
serving as a last-resort safeguard within the broader framework of European
legal integration.
24 Article 4(2) TEU
stipulates that “the Union shall respect the equality of Member States before
the Treaties as well as their national identities, inherent in their
fundamental structures, political and constitutional, inclusive of regional and
local self-government.” Fundamental constitutional structures within the
meaning of Article 4(2) TEU can encompass a wide range of core constitutional
principles, including specific expressions of democracy or the rule of law in
Member States. However, the CJEU’s case law on the extent to which Member
States may define and invoke their own constitutional identity remains
inconsistent and highly context-dependent. For instance, in the M.A.S. and M.B.
rulings involving the Italian Constitutional Court, the CJEU showed cautious
openness to national constitutional reservations and signalled a willingness to
engage in dialogue with national constitutional courts. In contrast, in cases
involving the Romanian Constitutional Court’s constitutionally controversial jurisprudence,
the CJEU rejected the admissibility of both identity review and ultra vires
review under EU law.
25 The
interpretation of the wording, structure, history, and purpose of Article 4(2)
TEU confirms its character as a reference to national constitutions and the
authority of national constitutional courts to define constitutional identity.
The wording – which states that national identity is expressed “in their”
fundamental constitutional structures – clearly points to domestic
constitutions as the relevant legal source. Structurally, the provision
complements Articles 4(1) and 4(3) TEU and establishes a binding limit on the
Union’s integrative reach. Historically, the travaux préparatoires of the
Constitutional Treaty show that responsibility for safeguarding constitutional
identity was deliberately left to the Member States, in order to prevent a
creeping expansion of EU competences. In terms of purpose, Article 4(2) is
meant to protect core constitutional choices from being overridden by Union
law. It functions similarly to self-judging clauses in international law, which
allow states to make their own determinations, subject only to limited review.
In this way, the provision establishes a direct link between Union law and
national constitutional law and forms a key element of the EU’s composite
constitutional structure. As a counterpart to national identity clauses such as
Article 79(3) of the German Basic Law, Article 89(5) of the French Constitution,
or Article 9(2) of the Czech Constitution, it opens Union law to core
components of national constitutional orders. Defining what constitutes
national identity ultimately falls to national constitutional courts, in line
with the division of responsibilities in the European constitutional court
network, while the CJEU is limited to checking for arbitrariness or abuse.
26 In narrowly
defined exceptional cases, Article 4(2) TEU leads to a systemic suspension of
the primacy of EU law and constitutes a procedural exception to the CJEU’s
monopoly of interpretation. This consequence is inherent in Union law itself,
since both the principle of conferral and the protection of national
constitutional identity define structural limits to the scope of primacy. In
narrowly defined exceptional cases, Article 4(2) TEU leads to a systemic
suspension of the primacy of EU law and constitutes a procedural exception to
the CJEU’s monopoly of interpretation. This consequence is inherent in Union
law itself, since both the principle of conferral and the protection of
national constitutional identity define structural limits to the scope of primacy.
While the obligation to respect national identity under Article 4(2) TEU is
generally relative, it becomes absolute where the core elements of
constitutional identity are at stake. This core includes those values,
structural principles, and norms that, under a Member State’s own
constitutional order, are categorically excluded from being transferred to the
Union – either because they are formally entrenched or because they are
considered non-transferable in structural terms. Even where national constitutional
principles coincide with the fundamental values enshrined in Article 2 TEU,
their particular national expression enjoys absolute protection, precisely
because those values themselves hold overriding importance within Union law.
What matters is not whether the national constitution contains an explicit
eternity clause, but whether – according to the domestic constitutional
understanding – it defines an inviolable sphere of sovereign
self-determination. In such cases, the obligation to respect national identity
is not subject to balancing or proportionality review. Accordingly, the Member
State’s interest in safeguarding this core outweighs the Union’s interest in
legal uniformity. While disregarding such identity would amount to a systemic
violation of constitutional self-government, the legal consequence within Union
law – namely, the inapplicability of the respective EU measure in that Member
State – is a limited and acceptable cost. The resulting impairment of
uniformity and effectiveness is consistent with the nature of the EU’s legal
order, particularly since the ultra vires review, as an expression of
democratic self-determination, also serves the values enshrined in Article 2
TEU. It is therefore grounded in primary law via Article 4(2) TEU and constitutes
a necessary procedural exception within the non-hierarchical, pluralistic
structure of the European constitutional order.
27 It has long been
assumed that only the identity review in the narrow sense corresponds
procedurally to this provision. However, as comparative constitutional analysis
shows, the ultra vires review – understood as a democracy-protecting form of
identity review – is also embedded in the constitutional structures of numerous
Member States. This applies particularly where it serves, as in the German and
Czech constitutional traditions, to safeguard popular sovereignty or sovereign
statehood. A qualified overreach of competences breaks the necessary link of
democratic legitimacy between Union action and the national constitutional order,
thereby infringing upon the constitutionally protected core of democratic
identity. In such cases, the ultra vires review functions as the procedural
mechanism for preserving this core, and must therefore be regarded not only as
an expression of domestic identity clauses – such as Article 79(3) of the
German Basic Law or Article 9(2) of the Czech Constitution – but also as a
review mechanism permitted under Union law by virtue of Article 4(2) TEU. The
jurisprudence of various national constitutional courts confirms this
classification. Ultra vires review thus constitutes a procedurally legitimate
expression of the Union’s obligation to respect national identity, reflecting
both the multidimensional nature of the primacy principle and the institutional
logic of the European constitutional court network.
No exclusion on the basis of conflicting EU
law
28 From the CJEU’s
perspective, ultra vires review by Member State constitutional courts violates
EU law for several reasons: it threatens the uniformity and effectiveness of EU
law, challenges the CJEU’s exclusive authority to declare EU acts invalid, and
undermines the principle of equality among Member States and their citizens. However,
these objections are not convincing from a doctrinal and legal-theoretical
standpoint.
29 Ultra vires
review does not undermine the CJEU’s exclusive authority to annul EU legal
acts. While both the jurisprudence established in the Foto-Frost judgment and
Article 267(1)(b) TFEU prohibit national courts from declaring EU acts invalid,
national courts are not categorically barred from examining whether such acts
exceed the competences conferred on the EU. When a national constitutional
court reviews the scope of EU law on the basis of its act of assent, it applies
a distinct standard – as confirmed by comparative constitutional law. This is
not a parallel review of EU law, but a narrowly limited control, typically
confined to manifest excess or arbitrary transgression of conferred competence.
On the remedial level, a finding that an EU act is ultra vires does not
invalidate it across the European Union; it merely renders the act inapplicable
within the respective national legal order. Furthermore, the strict separation
between the procedural question of Quis iudicabit? and the substantive
principle of conferral appears to be a politically motivated construct – one
that effectively grants the CJEU de facto authority over the very scope of its
own powers (i.e. the judicial competence over competences).
30 Moreover,
isolated ultra vires reviews can, in fact, strengthen the EU legal order in the
medium and long term. They help build trust in the European integration
process, as Member States are more willing to transfer additional competences
when assured that the limits of such transfers will be respected. Conversely,
if competences gradually extend beyond their original conferral, thereby
weakening the link between direct applicability and the principle of conferral,
the effectiveness and credibility of EU law risk being undermined.
31 The Member
States have not – and, indeed, could not – conferred upon the CJEU the
authority to determine the limits of its own judicial competence, as doing so
would inherently restrict their own constitutional identity and spheres of
competence. This is because the constitutional core of most Member States, often
entrenched or unamendable, impose strict limits on the transfer of sovereign
powers. The constitutional clauses authorizing the application of EU law only
extend to acts adopted within the limits of conferred competences and consistent
with national constitutional identity. This logic is reflected in Article
19(1), second sentence, TEU, which explicitly ties the CJEU’s jurisdiction to
the principle of conferral.
32 Despite the CJEU’s
recent explicit rejection of ultra vires review – albeit in the context of
rulings involving constitutionally compromised courts – its judgment in M.A.S.
and M.B. (Taricco II, 5 December 2017) contains indications that the Court
acknowledges the legitimacy of constitutional review reservations. This
effectively amounts to an exception to its asserted exclusive authority over
competence disputes (judicial competence over competences). The ruling suggests
a de facto recognition of identity review or, at the very least, a greater
deference to national constitutional identity when weighed against the primacy
and uniform application of EU law.
33 The CJEU’s new
line of reasoning – seeking to justify absolute primacy and a comprehensive
monopoly of jurisdiction through the principle of equality in Article 4(2),
sentence 1 TEU – suffers from fundamental methodological flaws and is therefore
unconvincing from the outset. It misinterprets the wording of Article 4(2) TEU,
which imposes obligations solely on the Union, not on the Member States,
ignores the internal structure of the provision, which expressly balances the
equality of Member States with the respect for their national identities, and
disregards its purpose as a protective provision in favour of the Member States
rather than as a tool to expand Union competences. Moreover, it rests on a
misapprehension of the function of the principle of equality within the EU
legal order. Where a situation falls outside the scope of Union law, the
principle of equality derived from it is inapplicable from the outset.
Accordingly, the CJEU’s argument is circular, because ultra vires review, by
definition, concerns precisely those cases where Union law is not applicable.
34 Since ultra
vires review is not only compatible with the EU Treaties but also rooted in
them, the involvement of national constitutional courts should be recognized as
a general principle of EU law. Ultra vires review is grounded in the
foundations of international law and the constitutional evolution of the EU
legal order. It represents a procedural and institutional expression of the
dual nature of the principle of conferral and safeguards the separation of
powers within the constitutional court system – particularly, with respect to
the legitimacy of European democracy. This review mechanism is justified under
Article 4(2) TEU as a treaty-based exception to the CJEU’s exclusive authority
to annul EU acts. As a legal concept, the ultra vires procedure reflects the
compound structure of the EU, composed of interlinked constitutional systems
and courts. Given the exceptional nature of this general legal principle, both
the burden and the authority to justify invoking ultra vires review rest with
the constitutional and supreme courts of the Member States. This approach
creates a balanced legal framework that preserves the effectiveness and uniform
application of EU law, while ensuring that ultra vires reviews remain legally
contained and subject to clear procedural safeguards.
In summary, ultra vires review should be
recognised as a structural element of the European legal order. As a procedural
expression of the principle of conferral and as a safeguard for constitutional
identity under Article 4(2) TEU, it serves a critical democratic and legal
function. Rather than contradicting Union law, it preserves the legitimacy of
EU integration by ensuring that the division of competences remains
constitutionally anchored. The next and final part of this blogpost will
examine how ultra vires review can be institutionalised within the existing
framework of EU law – not as a threat to legal unity, but as a mechanism for
structured constitutional dialogue.
Institutionalising Ultra Vires Review: The
Four-Tier Test for Constitutional Courts
The following analysis outlines four cumulative
stages that must be observed when invoking ultra vires review within the
European constitutional framework. Rather than undermining the primacy of Union
law, this structured procedure enhances mutual trust and legal certainty among
Europe’s constitutional courts. It clarifies the limited and exceptional
conditions under which national courts may act as guardians of their
constitutional mandates – while safeguarding the rule of law, democratic
legitimacy, and the institutional balance of the EU’s composite legal order.
1 The involvement
of Member State constitutional courts in the common ultra vires procedure is
based not only on their respective national constitutions and acts of assent,
but also on Articles 2, 5(2), and 4(2) TEU. Read together with Articles 4(3)
and 19 TEU, these treaty provisions give rise to four substantive requirements
– or stages – of the ultra vires procedure as a legal concept under EU law.
First, there must be a violation of the principle of conferral or of the integration
programme as enshrined in Articles 5(2) and 4(2) TEU. At every stage, ultra
vires review must comply with the principle of sincere cooperation (Article
4(3) TEU), respect the judicial function of the CJEU pursuant to Article 19
TEU, and fulfil its role as a democratic safeguard mechanism in line with Article
2 TEU, ensuring the legitimacy of EU action.
2 At the first
stage, there must be a legal act that exceeds the competences conferred upon
the EU. An ultra vires act exists where EU institutions act without a proper
legal basis, go beyond the conditions set for the exercise of their powers, or
breach prohibitive norms, thereby infringing on the competences of the Member
States. It is important to note that neither the obvious nature nor the particular
gravity of a competence breach is a requirement under EU law; such thresholds
cannot be derived from Article 5(2) TEU. In preliminary ruling proceedings
under Article 267 TFEU, it is sufficient for a national constitutional court to
have doubts about whether an EU measure falls within the Union’s competences. If
the court considers the case to involve an ultra vires act, it refers the
question concerning the scope of Union law to the CJEU. The ultra vires
procedure thus initially differs from an ordinary preliminary reference only in
that it is triggered not by any legal error, but specifically by a suspected
overstepping of competences. The decisive difference arises only at the stage
of assessing the CJEU’s response – namely, in the standard of review applied in
ultra vires control.
3 At the second
stage, the constitutional courts of the Member States and the CJEU are required
to cooperate and engage in judicial dialogue within the framework of the
preliminary ruling procedure. From the perspective of EU law, ultra vires
review necessitates the involvement of the CJEU in the decision-making process,
as provided by Article 4(3) first subparagraph, Article 19 TEU, and Article 267
TFEU. From the perspective of national constitutional law, this cooperation is
equally required due to the constitutions’ openness to European law. As a
result, the ultra vires procedure constitutes a matter of shared
responsibility, which can only be fulfilled through mutual cooperation and
constructive dialogue in the context of the preliminary ruling process.
4 This requires the
constitutional courts of the Member States to submit a clear and well-reasoned
question to the CJEU, providing all the necessary elements for the Court to
reach a conclusive judgment on the ultra vires issue. The submission must
include detailed legal arguments indicating a possible overreach of
competences. This transparency is essential for resolving a competence dispute
through legal reasoning. There must be a realistic opportunity for one court to
recognise the other’s legal position as methodologically sound – or even to be
persuaded by it. A notable example of this cooperative approach is the GCC’s
referral in the OMT case. The GCC comprehensively explained why it believed the
OMT decision violated Article 119 TEU, Article 127(1) and (2), and Article 123
TFEU. At the same time, it demonstrated its willingness to cooperate by allowing
room for the CJEU to interpret the legal issues in a way that aligned with its
conferred competences, thereby upholding the spirit of judicial dialogue within
the preliminary ruling procedure.
5 At the third
stage, the CJEU is responsible for interpreting EU law, though its decisions
remain subject to methodological scrutiny by the constitutional courts of
the Member States. If a ruling fails to meet methodological standards, the CJEU
exceeds its mandate under Article 19 TEU and may be overruled through ultra
vires review. The CJEU’s authority to interpret EU law is derived from the
Member States via the act of assent, as codified in Article 19(1) subparagraph
1, sentence 2 TEU. However, this authority is no longer democratically
legitimised if the interpretation goes beyond what Member States could
reasonably foresee when granting assent; this is particularly the case when the
CJEU tends to judicial legislating rather than interpreting the law. The CJEU
clearly oversteps its jurisdiction when it fails to respect the methodological
boundaries of judicial interpretation. This lack of methodological
appropriateness can take several forms: (a) contradictions and inconsistencies
in case law that affect the outcome, (b) disregard for standard methods of
legal interpretation, (c) failure to engage with arguments raised by the referring
court, (d) arbitrary judicial development, and (e) complete neglect of
constitutional standards in its review. In such cases, the effective control of
jurisdiction is no longer ensured, and the fallback function of national
constitutional courts is reactivated as to protect the division of competences
and uphold the legitimacy of EU action.
6 The CJEU’s Weiss
judgment illustrates an ultra vires ruling that lacks methodological
appropriateness due to internal contradictions and inconsistencies (a). Specifically,
the Court applied the proportionality test to EU institutions in a far more
superficial manner – without justification – than it typically does when
reviewing acts by Member State authorities. Furthermore, the CJEU’s complete
disregard for the economic policy implications of the PSPP conflicted not only
with its reasoning in Gauweiler but also with its general approach in other
areas of EU law.
7 A further serious
methodological error (b) lies in the CJEU’s failure to apply the established methods
of legal interpretation – such as textual analysis, historical context,
systematic structure, teleological reasoning, and comparative law. The
constitutional traditions of the Member States set boundaries for European
legal methodology and require that the CJEU’s interpretative approaches remain
consistent with these traditions. CJEU rulings must be sufficiently reasoned to
allow for public scrutiny and review by other courts, as mandated by Article
36(1) of the CJEU Statute and Article 87(m) of the CJEU Rules of Procedure. If
the CJEU disregards relevant facts or the arguments raised by parties to the
case, this may result in legally unintelligible outcomes. A notable example is
the Landtová judgment, in which the CJEU ignored both the wording of the
European Migrant Workers Regulation and the historical context surrounding the
dissolution of Czechoslovakia.
8 Based on its
judicial function under Article 19 TEU and the principle of sincere cooperation,
the CJEU is required to provide a sufficiently reasoned response to preliminary
references, particularly regarding alleged breaches of competence (c.). The
third category of judgments that fails to meet methodological standards thus
consists of CJEU rulings that do not adequately address the concerns raised by
the referring constitutional or supreme court. A key example is the CJEU’s
ruling in Weiss. Among other issues, the GCC asked whether the PSPP infringed
Article 119, Article 127(1) and (2) TFEU, as well as Articles 17–24 of the
Protocol on the Statute of the ESCB and the ECB. The GCC identified the ECB’s
failure to properly assess the proportionality of its measures as a central
issue in determining whether it had acted within its competence. Specifically,
the GCC was concerned about the economic policy effects of the ECB’s measures,
which had previously gone unexamined. However, the CJEU did not take these
detailed objections seriously and failed to engage with the economic impact in
a thorough or coherent way. As a result, a proper proportionality assessment,
in line with established legal methodology, was not carried out.
9 Fourth, arbitrary
judicial lawmaking constitutes a case of methodological failure (d.). A clear
example is the CJEU’s Mangold judgment, where the Court “created” the Union law
principle prohibiting age discrimination based on a questionable and
insufficient comparative analysis, without identifying a clear textual,
structural, or historical basis in the Treaties. This overstepped the
permissible bounds of judicial interpretation, amounting instead to an
unauthorised amendment of primary law. Legitimate judicial development of the
law serves to fill unintended gaps, resolve conflicts of fundamental values,
and ensure fair adjudication in individual cases, but it is strictly limited:
it must not result in legislative correction, encroach upon areas reserved for
political decision-making, or undermine the principle of conferred powers.
Furthermore, any judicial development must meet heightened requirements of
justification; the comparative analysis must be comprehensive, transparent, and
logically coherent, and particular care must be given to respecting the
division of competences between the Union and the Member States.
10 The fifth
category in which the CJEU manifestly exceeds its jurisdiction arises when it
fails to fulfil its institutional judicial role and thereby falls short of the
constitutional standards enshrined in Article 19 in conjunction with Article 2
TEU. This occurs, for example, when the Court fully or partially fails to
fulfil its duty of judicial review – particularly with respect to executive or
independent institutions – or when it applies the intensity of review
arbitrarily (e.). A clear example of this is once again the Weiss judgment,
where the CJEU effectively abdicated its judicial oversight role by conducting
only a cursory review limited to assessing whether the ECB had committed “obvious”
overreaches of its mandate. The Court merely asserted the proportionality
between monetary policy measures and their economic consequences, rather than
actually examining their consequences. This represents a fundamental
methodological error: proportionality between ends and means cannot be meaningfully
affirmed without first identifying and evaluating the actual effects. Such an
examination was not even possible in this case, as the CJEU never clearly
identified the economic implications of the ECB’s actions. This fifth category
of judgments, which depart from established legal methodology by neglecting
rule-of-law standards in judicial review, directly underscores the need for
ultra vires control. It serves to prevent gradual, unchecked shifts of power
towards the EU level and safeguards Member States’ authority over their own
competences as well as the democratic self-determination of their citizens.
11 Although ultra
vires review is a tool for safeguarding the legitimacy of EU action, it must be
understood within the broader context of EU law. It is rooted in the democratic
principles of the European Union and contributes to maintaining the separation
of powers and upholding the rule of law. Therefore, its legitimacy and
application – especially during the fourth stage of the procedure – are tied to
compliance with the rule-of-law requirements set out in Article 2 TEU.
12 Constitutional
courts retain a limited degree of discretion in interpretation and judgement.
This means that, in exceptional cases, both the activation and rejection of
ultra vires review by different Member State constitutional courts may be
permissible with respect to the same legal issue. This outcome is also
consistent with the EU’s interconnected legal structure, particularly given
that the CJEU’s jurisdiction is derivative and, unlike the constitutional
courts of the Member States, the CJEU does not possess the competence to
determine the scope of its own powers.
13 Article 2 TEU
implies a specific prohibition of abuse of rights within Union law, which also
limits the scope of ultra vires review. Such review is only permissible where
it serves its purpose of safeguarding democratic legitimacy within the Union
through constitutional courts of the Member States. It becomes abusive – and
therefore contrary to Union law – where it is functionally disconnected from
that purpose, for example: (1) where the subject matter is not clearly limited,
(2) where the ruling is not embedded in a consistent, EU-friendly line of
jurisprudence, (3) where the judiciary is visibly instrumentalized by the
executive, or (4) where the legal consequences are left unclear and risk
systemic disruption. In these cases, the review no longer safeguards
constitutional identity but undermines the legal order. The CJEU may intervene
in such situations but is limited – under Article 4(2) and Article 4(3) TEU – to
a review for abuse or arbitrariness, following a good faith standard.
14 Ultra vires
review must also be understood within the broader context of the horizontal
network of constitutional courts. It should not be viewed in isolation but in
light of the shared constitutional traditions and judicial decisions of the
Member States. This requires mutual consideration of rulings by other
constitutional courts. Any departure from these decisions must be appropriately
justified and take into account both national and EU legal perspectives. Such
an approach ensures coherence in judicial reasoning and alignment with European
values and legal principles.
15 In summary,
ultra vires review should be understood as a shared responsibility within the
European network of constitutional courts. Legally, Member State constitutional
courts retain ultimate authority to deliver final judgments concerning their
own legal systems. At the same time, the CJEU holds a “right of first access”
based on its interpretative monopoly, enabling it to resolve the vast majority
of jurisdictional disputes with legal certainty. However, this presupposes that
the CJEU exercises a level of judicial scrutiny that genuinely safeguards the
principle of conferral and, by extension, the (national) sovereignty of the
Member States. This division of roles aligns with the institutional functions
of the CJEU and the constitutional courts in the European constitutional court
system. The CJEU, as the Union’s court, is responsible for interpreting and
ensuring the effectiveness of EU law and is particularly well positioned to do
so given its institutional proximity to Union-level issues. In contrast, the
constitutional courts of the Member States are not tasked with reinterpreting
EU law, but rather with safeguarding national constitutional identity. By
observing this task, they also preserve the coherence of the EU’s heterogeneous
and pluralistic constitutional value system.
16 The following
thesis may serve as a forward-looking conclusion: The GCC’s PSPP judgment may
well be remembered as the starting point for establishing effective competence
control as a shared responsibility at the level of EU law. Just as the GCC’s Solange
I case law was initially met with strong criticism but ultimately played a key
role in developing robust European fundamental rights protection, a similar
evolution may now be underway. The growing legal conviction among Member
States’ constitutional courts – that they may invoke democracy-protecting
constitutional reservations such as ultra vires review – is likely to motivate
the CJEU to fulfil its institutional judicial role with greater rigour, particularly
in complex jurisdictional matters at the intersection of the European composite
legal order. In doing so, the CJEU can contribute meaningfully to enhancing
legal certainty and legal confidence across the EU – two foundational elements
of the rule of law and key drivers of European integration in a legal
community. At the same time, it remains evident that if the CJEU consistently
and credibly reviews the limits of competences under EU law, the constitutional
courts of the Member States will have no cause to resort to ultra vires review.
Ultra vires review is not a relic of
constitutional nationalism, but a structured expression of judicial responsibility
in a pluralistic Union. When invoked under the four cumulative conditions
identified in this part – (1) a manifest breach of conferred powers, (2)
sincere judicial dialogue through the preliminary reference procedure, (3) a
demonstrable failure of the CJEU to meet the standards of legal methodology,
and (4) compliance with the democratic and rule-of-law principles of Article 2
TEU – it strengthens rather than weakens the authority of EU law. These
requirements ensure that ultra vires review is not exercised arbitrarily but
remains embedded in a framework of institutional cooperation, interpretative
discipline, and mutual respect. Properly understood, ultra vires review
complements the role of the CJEU by acting as a constitutional backstop: it
upholds the foundational balance between Union effectiveness and Member State
sovereignty. If the CJEU fulfils its institutional role with methodological
clarity and judicial restraint, ultra vires review will remain what it was
always meant to be – a principled exception, not a systemic threat.
