Heiko Sauer recently diagnosed a “course correction in European constitutional law”. In light of the Second Senate’s Egenberger judgment, he paints a picture of a Federal Constitutional Court (BVerfG) returning to calmer waters after the seismic aftershocks of the PSPP judgment (BVerfGE 154, 17). Sauer speaks of a “salutary deflation of ultra vires review” – even a “farewell” to the great battles surrounding European constitutional law. In his view, Karlsruhe’s reservations are being reduced to what they were originally meant to be: exceptional “last-resort” safeguards; hypothetical emergency brakes whose activation has faded into the far future. The prevailing tone is one of relief: the dissonance has become less noticeable, suggesting that harmony seems to be restored.

As tempting as this interpretation may be – driven by a desire for a harmonious cooperative relationship between courts –, it risks equating the mere absence of open conflict with structural pacification. I would like to both add to and modify Sauer’s thesis: institutionalisation, rather than the “deflation” of review, which just reduces its effectiveness, is the solution.

True cooperation requires rules for handling jurisdictional boundaries – an institutionalised interplay that treats disagreement not as unconstitutional “accidents” within the Union, but as essential dialogue. Ultra vires review is not a malfunction; when properly understood, it is a necessary institution of Union constitutional law itself.

No German Sonderweg: The European evidence

A central misunderstanding in the “deflation” discourse is the assumption that ultra vires review is a uniquely German phenomenon – a Karlsruher Sonderweg that is now slowly being reintegrated into the European mainstream. However, a systematic overview of European constitutional jurisprudence reveals a very different picture: European normality is, in fact, the rejection of an absolute, “competence-blind” primacy of EU law.

As long as the Member States continue to control the “if” and “how” of integration, ultra vires review is not a national quirk but the logical opposite of the European order of competences. While the CJEU claims absolute autonomy for Union law and a corresponding monopoly on adjudication, this absolute autonomy is a fiction – one rooted neither historically nor dogmatically in the Treaties. The EU is founded on the principle of conferral (Art. 5(1) sentence 1 and (2) TEU). This principle is not a mere political declaration of intent; it is the legal backbone of the Union. The Union remains a derived legal order; its legitimacy does not rest upon itself, but upon the will of the Member States and their constitutionally rooted, democratically steered mandates to apply the law.

This is not a German peculiarity; it is a European constitutional standard. Whether it is Article 23(1) sentence 2 of the Basic Law, Article 88-1 of the French Constitution, Article 90 of the Polish Constitution, or Article 11 of the Italian Constitution – they all open the national legal order to Union law while simultaneously defining its limits as the basis for its legitimacy.

The majority of national constitutional courts have established reservations that functionally correspond to the ultra vires review. In its Ajos judgment (Case 15/2014), the Danish Højesteret drew a clear red line and refused to follow the CJEU, citing the requirement of legal certainty in the Danish Constitution when it comes to the transfer of sovereign powers. In France, the Conseil Constitutionnel and the Conseil d’État employ a flexible balancing of principles (“identity review” or “equivalence tests”) to ensure that jurisdictional overreach does not hollow out the constitutional identity – as demonstrated in the French Data Network ruling (Conseil d’État, No. 393099). Similarly, in Czechia (Holubec, Pl. ÚS 5/12), Poland (K 18/04, prior to the rule of law crisis), and Italy (“Controlimiti”, cf. already Fragd, 232/1989), courts reserve the right to limit the primacy of Union law where fundamental constitutional values and popular sovereignty are at stake.

If we speak of “deflation”, we should not pretend that the PSPP judgment was an “accident” now being corrected. Rather, it was the most outspoken manifestation of a common legal belief across Europe: where the national constitution’s democratic mandate reaches its limit, the authority of Union law ceases.

From a disruptor to an institution of EU law

The current debate lacks a crucial shift in perspective: ultra vires review does not stand outside the Union’s legal framework; it is supported by the Treaties themselves. Ultra vires review should therefore be understood not as a disruptive factor, but as an institution of EU law. It is key for resolving the conflict.

The identity clause of Article 4(2) sentence 1 TEU obliges the EU to respect the national identities of the Member States, inherent in their core constitutional structures. This is not merely a courtesy to national capitals or non-binding political poetry, despite what appears to be a widespread understanding. It is a hard, justiciable legal norm with a strong claim to validity. With Article 4(2) TEU, Union law opens itself to the untouchable core elements of Member State constitutions, making their protection a Union-law obligation in its own right.

This is inextricably linked to the democratic principles of the Union, as laid down in Articles 2 and 10 TEU. The European Union derives its democratic legitimacy not from its own “people”, but from the constituent peoples of the Member States, mediated through national parliaments and the European Parliament. The principle of conferral is the guarantor of this democratic linkage: the Union may act only insofar as a transfer of competence has been democratically legitimised by national parliaments. A qualified jurisdictional overreach – an act ultra vires – is therefore never just a technical error in the distribution of powers; it is an assault on the principle of democracy itself. When Union organs seize mandates that were never given to them, they break the chain of democratic legitimacy and violate popular sovereignty, which, as a core component of national constitutional identity, enjoys the special protection of Article 4(2) TEU.

This observation must also be procedurally secured. If national constitutional courts were denied this instrument, the protection of constitutional identity would become an empty shell as soon as the CJEU failed to recognise or sanction a jurisdictional overreach. Ultra vires review is thus not an act of disobedience against Union law: it ensures that the limits of integration, as set out in the Treaties themselves, are not crossed by a creeping, contra legem expansion of competences.

The review by national constitutional courts thus secures the democratic legitimacy of the Union. The EU is a democracy legitimised through specific competences. When competences migrate without a mandate (“creeping competences”), citizen consent can erode.

Institutionalised interplay means that national constitutional courts and the CJEU do not function against each other but in a division of labour: the CJEU ensures uniformity (Art. 19 TEU), while national courts ensure the limits of conferral.

Proceduralisation instead of confrontation: A four-stage model

What does this interplay look like in practice? There can be no “wild” breakouts, no arbitrary refusal to comply with the law. An ultra vires review that complies with EU law must be strictly proceduralised. Only in this way conflicts can be transferred from the political to the legal level and resolved there.

Such an institutionalised procedure could – in broad terms – be conceptualised de lege lata in four stages, derived from the constitutional foundations of Articles 2, 4(2) and (3), and 5 TEU, and the legal protection guarantees of Articles 19 TEU and 267 TFEU:

First, the principle of conferral (Art. 5(1) and (2) TEU) requires a precise distinction between a simple legal error and an usurpation of competence. Not every erroneous application of law is an ultra vires act; there must be a structural breakout from the “integration programme” of the domestic act of approval. Such a breakout occurs when the Union acts in a field in which it lacks jurisdiction, or if it exercises an existing competence so excessively – by violating constitutive limits such as prohibitive norms or the principle of proportionality – that it effectively amounts to an expansion of competences without a legal basis in the treaties.

Second, the procedural safeguard of the judicial duty of cooperation under Article 4(3) TEU and Article 267 TFEU comes into play. Before a Member State constitutional court leaves a Union measure unapplied in its own jurisdiction, it is required to make a preliminary reference and engage in dialogue with the Court of Justice. If doubts exist regarding the legal basis, the path to Luxembourg must be taken; dialogue is not an option but a Union-law necessity for clarifying the legal situation. The BVerfG demonstrated this in the OMT proceedings (BVerfGE 134, 366): it set out in detail why it saw an overreach of competence but gave the CJEU the opportunity to provide its own interpretation.

Third, the allocation of jurisdiction under Article 19 TEU must be respected: the CJEU has the mandate to “ensure that in the interpretation and application of the Treaties the law is observed.” However, in doing so, the CJEU must employ comprehensible methods. This is where Sauer perhaps underestimates the “deflation” in his analysis. When the BVerfG accepted the CJEU’s decision in Egenberger, it did this to test the “methodological integrity” of the CJEU’s response, not out of resignation. If, however, the CJEU utterly disregards methodological standards – by ignoring obvious facts, distorting the wording, or engaging in arbitrary judicial law-making – it leaves the ground of “interpreting the Treaties” and engages in inadmissible norm-setting. To preserve legal certainty here, refined categories for such serious methodological errors are required.

The CJEU’s Weiss judgment (C-493/17) was a cautionary tale of a methodological deficit, in which the Court effectively ignored the economic policy implication of the ECB’s policy, making a proportionality test impossible. In Egenberger, by contrast, the BVerfG saw the interpretation of the Anti-Discrimination Directive as methodologically tenable. That is the difference: the CJEU judgment is not followed blindly (“deflation”); instead, it follows a thorough examination (“institutionalisation”). The BVerfG reserves the right of review, but exercises it with restraint, provided the CJEU works in a methodologically coherent manner.

Fourth, the procedure must be protected against abuse. Ultra vires review must never serve to dismantle rule-of-law standards or evade the Union’s fundamental values. Warning examples of such instrumental abuse can be found in the jurisprudence of the politically captured Polish Constitutional Tribunal (e.g., judgment K 3/21) and the Hungarian Constitutional Court (especially Decision 22/2016). Legal certainty can only be created here through a precise categorisation of cases based on Article 2 TEU. National identity must not become a cloak for authoritarian structures: those who dismantle the rule of law internally cannot invoke it against the Union.

No Fear of Institutionalised Dissonance

Sauer’s “elegy” for the great confrontations is premature, as the institutional questions have not yet been conclusively resolved. Questions of competence will not disappear as long as the Union develops dynamically, and crisis management is regularly accompanied by the expansion of competences. Simply downplaying them is not enough. We should free the ultra vires review from the stigma of alleged nationalism and firmly integrate it as a procedural element within the Union’s architecture.

The PSPP judgment may have been perceived as a shock, but historically, it could be the birth of effective competence monitoring as a shared task. Much like the Solange I jurisprudence (BVerfGE 37, 271) once compelled the CJEU to take fundamental rights protection seriously, the ultra vires reservation today forces the Court to take its role as the guardian of the competence order more seriously, rather than acting unilaterally as a “motor of integration”.

An institutionalised procedure forces parties to provide reasons and engage with the arguments of the other side. It transforms a power struggle into a discourse. A Union that takes its own limits seriously and guarantees compliance through a cooperative procedure is ultimately more harmonious, more legitimate, and more effective than a Union that treats criticism of its competences as lèse-majesté.

True stability is not created by constitutional courts being silent but by integrating them into a structured European procedural framework. Recent jurisprudence from European constitutional courts makes it increasingly clear: ultra vires review is here to stay. Those who sing its elegy fail to see that it is precisely the legally hemmed-in possibility of saying “no” that makes the “yes” to European integration constitutionally more sustainable. This is the “institutional interplay” that we must continue to develop, even after Egenberger.