Are Member States the Guardians of EU Values? Notes on an Initiative of the Dutch House of Representatives Aimed at Initiating Proceedings under Article 259 TFEU against Slovakia

The infringement procedure as a tool for the systemic protection of the fundamental values of the Union

As is well known, to overcome the difficulties posed by the control mechanism provided for in Article 7 TEU, the protection of the fundamental values of the European Union has primarily been pursued through the EU Court of Justice’s action. The infringement procedure governed by Articles 258 et seq. TFEU has gained particular momentum in this regard. This has led to a structural evolution of that procedure: from an instrument aimed at restoring supranational legality in the face of ordinary violations by Member States of their obligations under the Treaties¹, it has (also) become a mechanism for ascertaining systemic breaches of the identifying features of the EU legal order, i.e. the values on which that legal order is based, which are set out in Article 2 TEU².

The turning point came thanks to the judicial activism of the Court of Justice, which, starting with its now-famous ruling in the Associação Sindical dos Juízes Portugueses case³, emphasized the obligations that give concrete form to the values mentioned in the Treaties. Since then, the Court of Justice has been called upon to rule on numerous infringement proceedings brought by the European Commission under Article 258 TFEU, primarily concerning episodes of rule of law backsliding in EU States that have been members for a shorter period. Moreover, this development has triggered both a doctrinal and institutional debate on the self-executing scope of the values of the Union⁴, on which clarification by the Court of Justice is desired and could come pretty quickly, given the imminent delivery of the judgment on the compatibility with Article 2 TEU of a series of legislative acts adopted by Hungary and having LGBTI content. In the case in question, Advocate General Ćapeta identified «the negation of the values» set out in the EU Treaty as the criterion that could give rise to a finding of a self-standing infringement of Article 2 TEU⁵.

The motion of the Dutch House of Representatives of 16 October 2025

It is precisely based on a recent constitutional reform adopted by the Slovak Republic⁶, which, among other things, has implications for the LGBTI community, that a new and significant development could emerge regarding the use of infringement proceedings to protect the fundamental values of the European Union. On October 16, 2025, during the debate on the European Council of 23 and 24 October 2025, the Dutch House of Representatives (Tweede Kamer der Staten-Generaal) adopted a motion requesting the Government to initiate proceedings under Article 259 TFEU against the Slovak Republic. More specifically, the motion clarifies that the adoption of the constitutional amendment at stake, which places national law above EU law and restricts the rights of LGBTI persons⁷ («constaterende dat Slowakije een grondwetswijziging heeft doorgevoerd waarbij het nationale recht boven het EU-recht wordt geplaatst en waarmee de rechten van lhbti-personen worden ingeperkt»), constitutes a clear violation of the EU Treaties («overwegende dat dit in strijd is met de EU-verdragen»)⁸.

The interstate infringement procedure outlined in Article 259 TFEU is, as is well known, a tool that is rarely used in the practice of Member States⁹. It has only been activated twelve times, seven of which were after the entry into force of the Treaty of Lisbon¹⁰. On three separate occasions, the applications were dismissed, and the case was removed from the register¹¹. Until now, almost all of the proceedings have been characterised by intense political tensions between the states concerned and the presence of significant national interests, the protection of which has been linked to the need to restore the defendant state’s compliance with supranational law¹². Thus, to give just a few examples, the Kingdom of Spain considered that it could protect its claims against Gibraltar by invoking the United Kingdom’s compliance with the provisions relating to the electoral rights of European citizens, while the Republic of Slovenia brought an action against the Republic of Croatia, arguing that the latter’s failure to comply with an arbitration award for the final settlement of the territorial dispute between the two States could also have resulted in an infringement of EU law applicable in the disputed areas. Furthermore, Hungary initiated infringement proceedings against the Slovak Republic for violating the mobility rights associated with the European citizenship of the Hungarian President (who was denied entry into Slovak territory to attend a ceremony in the city of Komárno), while the Republic of Latvia has taken action to sanction the violation, against it, of the obligations incumbent on the Kingdom of Sweden under Directive 2014/49/EU on deposit guarantee schemes¹³. Two proceedings are now pending before the Court, which are also characterised by a ‘bilateral’ logic, so to speak: the first was brought by Poland against Germany for breach of obligations under Regulation (EC) No 1013/2006 on shipments of waste¹⁴ in relation to six shipments to Polish locations; the second was brought by Italy against Austria for breach of Articles 34 and 35 TFEU following the adoption by the latter country of an order restricting night-time transit on the A12 motorway in the Inn Valley¹⁵.

Against this background, the initiative of the Tweede Kamer could mark a significant turning point, in line with what has been argued in the past by some legal scholars who have examined possible remedies for breaches of EU values by Member States other than those provided for in Article 7 TEU¹⁶. This is because the position taken by the House of Representatives appears to be motivated not by the intention to protect national interests ‘threatened’ by infringements of EU law attributable to another Member State, but by the desire to restore supranational legality in the general interest of the European Union and its Member States in the face of a breach of fundamental elements of the legal system. It should be noted that this is not the first time that the Dutch Parliament has taken such a position. Back in November 2020, the House of Representatives adopted a motion on the judicial reforms introduced in Poland, describing the measures approved by that country as a serious threat to the rule of law and urging the Dutch government to take the necessary steps to bring the EU Member State before the Court of Justice, preferably in cooperation with other Member States¹⁷. In that case, the EU’s response took the form of a series of actions under Article 258 TFEU brought by the European Commission[18]. This would appear to be a possible outcome in the case in question as well. In fact, on 21 November 2025, the European Commission announced its decision to initiate infringement proceedings under Article 258 TFEU against Slovakia¹⁹. The decision was motivated by the fact that, by adopting the controversial amendment to the Constitution, Slovakia would have violated certain fundamental principles of European Union law, particularly the principles of primacy, autonomy, effectiveness, and uniform application of supranational law²⁰.

More generally, we must not forget the fact that the Netherlands is known for its attitude, based on the constitutional duty enshrined in Article 90 of the Dutch Constitution²¹, of promoting international compliance with erga omnes (partes) obligations. A clear example of this attitude are the recent initiatives taken by the country to encourage, first, the revision and then the suspension of the Euro-Mediterranean Association Agreement between the European Union and its Member States, on the one hand, and the State of Israel, on the other, due to the latter’s violation of the so -called ‘essential elements’ clause set-out in Article 2 of that Agreement²².

The foregoing, however, does not diminish the scope of the parliamentary initiative of October 2025. If anything, the above considerations help to put that initiative into context, suggesting that its potential scope should be clarified from a supranational perspective.

Article 259 TFEU and mutual membership

In its famous ruling in the Achmea case, the Court of Justice outlined the foundations of what can be described as ‘mutual membership’ in the context of the European Union: «EU law is […] based on the fundamental premiss that each Member State shares with all the other Member States, and recognises that they share with it, a set of common values on which the Union is founded, as stated in Article 2 TEU. That premiss implies and justifies the existence of mutual trust between Member States that those will be recognised, and therefore that the law of the EU that implements them will be respected»²³. The legal integration promoted at the supranational level, which stems from the sharing of fundamental values through a process leading to their Europeanisation²⁴, determines a strong reciprocity in relations between Member States, so that the behaviour of one Member State, starting with behaviour that constitutes a violation of the common foundations of the European construct, inevitably has repercussions on the others. This is why, as the Court points out in Achmea, each Member State must ensure strict compliance with EU law, starting with its foundations, in accordance with the principle of sincere cooperation²⁵. Or, to quote Kochenov, «since all the Member States are in the same boat, they have a vivid interest in ensuring sustained compliance with EU law by their peers»²⁶. Only in this way, moreover, can it be ensured that the Union truly respects the equality of States before the Treaties, as required by Article 4(2) TEU²⁷.

From this perspective, recourse to Article 259 TFEU is far from being a reaction dictated by intergovernmental logic, which is most clear in the political infringement procedure under Article 7(2) TEU. Instead, it is a strongly integrationist response, which transforms the bilateral logic of interstate relations into a spirited interaction inspired by mutual membership, in which it is no longer necessary to demonstrate that the failure of another Member State has caused actual harm to the applicant State. Not only that²⁸. The mandatory intervention of the European Commission in the procedure further highlights the pursuit of the EU interest that should (always!) characterise its activation²⁹.

Conclusions

At a time like the present, when the fundamentals of international law are being called into question, several States are rediscovering their role in ensuring the fulfilment of erga omnes (partes) obligations. One of the most significant illustrations of this trend is undoubtedly the increase in both the number of legal proceedings brought before the International Court of Justice for breaches of erga omnes obligations and the number of interventions before that Court – pursuant to Articles 62 and 63 of its Statute – based on similar or identical grounds³⁰.

Mutatis mutandis, the infringement procedure provided for in Article 259 TFEU expresses a similar logic at the supranational level. In this contribution, taking as its starting point the recent initiative taken by the Dutch House of Representatives, it has been argued that more decisive recourse to this procedure by Member States could be a valuable tool for consolidating the foundations on which mutual membership to the Union is based, namely the values enshrined in Article 2 TEU, thus pursuing a general interest which should constitute, to paraphrase the famous obiter dictum of the International Court of Justice’s ruling in the Barcelona Traction case, «the concern of all [the Member] States»³¹. In doing so, Member States would act as trustees protecting the essence of the integration process and fully expressing the need for sincere cooperation in pursuing the objectives of the Treaties, which, as highlighted by the Court of Justice in Achmea, is a fundamental guarantee of mutual trust between the States themselves³². This, of course, without prejudice to the entirely complementary role that the European Commission can play in its capacity as ‘guardian of the Treaties’³³, and the still open question, mentioned at the beginning of this contribution, of whether EU values can be given immediate binding force.

Furthermore, in purely statistical terms, an increase in proceedings based on Article 259 TFEU – which is already partly evident in the numbers of post-Lisbon procedures³⁴ – should help to reverse the current trend emerging from the judgments handed down by the Court of Justice in the proceedings brought to date: in only three cases, in fact, have the Luxembourg judges upheld – in whole or in part – the charges brought by the applicant State³⁵.

1 See A. Barav, Failure of Member States to Fulfil Their Obligations under Community Law, in Common Market Law Review, 1975, p. 369 ff.

2 On this development, see, among others, M. Schmidt, P. Bogdanowicz, The Infringement Procedure in the Rule of Law Crisis: How to Make Effective Use of Article 258 TFEU, in Common Market Law Review, 2018, p. 1061 ff.; M. Bonelli, Infringement Actions 2.0: How To Protect EU Values before the Court of Justice, in European Constitutional Law Review, 2022, p. 30 ff.; P. Mori, L’uso della procedura di infrazione a fronte di violazioni dei diritti fondamentali, in Il Diritto dell’Unione europea, 2018, p. 363 ff.; A. Circolo, Il valore dello Stato di diritto nell’Unione europea. Violazioni sistemiche e soluzioni di tutela, Naples, 2023, p. 197 ff.

3 Court of Justice, 27 February 2018, Case C-64/16, Associação Sindical dos Juízes Portugueses, ECLI:EU:C:2018:117.

4 On this point, see L.S. Rossi, ‘Concretised’, ‘Flanked’, or ‘Standalone’? Some Reflections on the Application of Article 2 TEU, in European Papers, 2025, p. 1 ff.

5 Opinion of Advocate General Čapeta, 5 June 2025, Case C-769/22, Commission v Hungary, ECLI:EU:C:2025:408, paras. 237 et seq.

6 An English-language version of the 23^rd amendment to the Slovak Constitution, adopted on 26 September 2025, is reproduced in the Urgent Opinion issued by the Venice Commission on 24 September 2025, which refers to it. See European Commission for Democracy through Law of the Council of Europe, Slovak Republic Urgent Opinion on the Draft Amendments to the Constitution, doc. CPL-PI(2025)011, <https://www.venice.coe.int/webforms/documents/?pdf=CDL-PI(2025)011-e>. Cf. also M. Steuer, No Skyfall: The Twenty-third Amendment to the Slovak Constitution, in Verfblog, 20 October 2025, <https://verfassungsblog.de/slovakia-constitutional-amendment/>.

7 In fact, the amendment introduces a clause on national identity, which precludes any transfer of prerogatives to other entities (i.e., the EU) about matters related to it, as well as a series of provisions aimed at protecting the so-called ‘natural’ family.

8 Doc. 2025D44356. The Dutch-language text of the motion is available at the following link: <https://www.tweedekamer.nl/kamerstukken/moties/detail?id=2025Z19027&did=2025D44356>. It is important to note that, on the same date, a motion was also adopted calling on the Government to raise the issue of Slovak constitutional reform in the General Affairs Council, with a view to forming a coalition of Member States to initiate proceedings under Article 7 TEU against that EU country («verzoekt de regering om Slowakije in de Raad Algemene Zaken aan te spreken en een coalitie van EU-lidstaten te smeden om een artikel 7-procedure tegen Slowakije op te starten»). Doc. 2025D44365, <https://www.tweedekamer.nl/kamerstukken/moties/detail?id=2025Z19037&did=2025D44365>.

9 On this point, see G. Butler, The Court of Justice as an Inter-State Court, in Yearbook of European Law, 2017, p. 179 ff.; M. Condinanzi, C. Amalfitano, La procedura di infrazione dieci anni dopo Lisbona, in federalism.it, 2020, p. 217 ff., pp. 260-265.

10 Case 58/77, Ireland v France; Case 141/78, France v. United Kingdom; Case C-349/92, Kingdom of Spain v. United Kingdom; Case C-388/95, Kingdom of Belgium v. Kingdom of Spain; Case C-145/04, Kingdom of Spain v. United Kingdom, Case C-364/10, Hungary v. Slovak Republic; Case C-591/17, Republic of Austria v. Federal Republic of Germany; Case C-457/18, Republic of Slovenia v. Republic of Croatia; Case C-121/21, Czech Republic v. Republic of Poland; Case C-822/21, Republic of Latvia v. Kingdom of Sweden; Case C-730/23, Poland v. Germany; Case C-524/24, Italian Republic v. Republic of Austria.

11 Case 58/77, Ireland v. France, cit.; Case C-349/92, Kingdom of Spain v. United Kingdom, cit.; Case C-121/21, Czech Republic v. Republic of Poland, cit.

12 In this regard, see L. Prete, Infringement Proceedings in EU Law, Alphen aan den Rijn, 2017, p. 203; B. Schima, D. Eisendle, Art. 259 TFEU, in M. Kellerbauer, M. Klamert, J. Tomkin (eds.), The EU Treaties and Charter of Fundamental Rights: A Commentary, 2^nd ed., Oxford, 2024, p. 2393 ff., p. 2394.

13 Directive 2014/49/EU of the European Parliament and of the Council of 16 April 2024 on deposit guarantee schemes, in OJ L 173, 12 June 2014, p. 149 ff.

14 Regulation (EC) No 1013/2006 of the European Parliament and of the Council of 14 June 2006 on shipments of waste, in OJ L 190, 12 July 2006, p. 1 ff.

15 See also G. Agrati, Divieto di circolazione sull’Autostrada del Brennero: l’Italia presenta ricorso in Corte di giustizia e la Commissione interviene a sostegno, in this Journal, 2024, p. 257 ff.

16 D. Kochenov, Biting Intergovernmentalism: The Case for the Reinvention of Article 259 TFEU to Make It a Viable Rule of Law Enforcement Tool, in Hague Journal of the Rule of Law, 2015, p. 153 ff.; G. Íñiguez, The Enemy Within? Article 259 TFEU and the EU’s Rule of Law Crisis, in German Law Journal, 2022, p. 1104 ff.

17 Doc. 35570-VI-58, 26 November 2020, <https://www.tweedekamer.nl/kamerstukken/moties/detail?id=2020Z22968&did=2020D48543>.

18 A. Circolo, Il valore dello Stato di diritto nell’Unione europea, cit., p. 218 ff.

19 Cf. European Commission, November Infringement Package: Key Decisions, doc. INF/25/2481, 21 November 2025, <https://ec.europa.eu/commission/presscorner/detail/en/inf_25_2481>.

20 Ibid. Slovakia has been given two months to respond to the concerns raised by the Commission. On the European Commission’s initiative, see P. Faraguna, Revisione costituzionale contro primato. La Commissione apre una procedura di infrazione nei confronti della Slovacchia, in this Issue.

21 The article stipulates that the Government must promote the development of the international legal order. On this provision, see L. Besselink, The Constitutional Duty to Promote the Development of the International Legal Order: The Significance and Meaning of Article 90 of the Netherlands Constitution, in Netherlands Yearbook of International Law, 2003, p. 89 ff.

22 See Netherlands Urges Review of EU-Israel Trade Deal over ‘Catastrophic’ Gaza Aid Block, in The Guardian, 7 May 2025, <https://www.theguardian.com/world/2025/may/07/netherlands-urges-review-of-eu-israel-trade-deal-over-catastrophic-gaza-aid-block>; Dutch and Swedish Ministers Send Letter to EU Foreign Chief Calling for Israel Sanctions, in NL Times, 28 August 2025, <https://nltimes.nl/2025/08/28/dutch-swedish-ministers-send-letter-eu-foreign-chief-calling-israel-sanctions>.

23 Court of Justice, 6 March 2018, Case C-284/16, Achmea, ECLI:EU:C:2018:158, para. 34.

24 F. Casolari, Il processo di europeizzazione delle identità nazionali degli Stati membri: riflessioni sulle traiettorie del costituzionalismo europeo, in Quaderni AISDUE, special issue 1/2024, p. 267 ff.

25 Court of Justice, 6 March 2018, case C-284/16, Achmea, loc. cit. On the interaction between sincere cooperation and mutual trust, see M. Klamert, Structural Principles of EU Law, Oxford, 2025, pp. 113-114; F. Casolari, Leale cooperazione tra Stati membri e Unione europea. Studio sulla partecipazione all’Unione al tempo delle crisi, Naples, 2020, p. 113 ff.

26 D. Kochenov, Biting Intergovernmentalism, cit., p. 161.

27 See, most recently, F.L. Gatta, Il principio di uguaglianza degli Stati membri nel diritto dell’Unione europea, Milan, 2025, p. 250 ff.

28 For a different view, highlighting the hybrid nature (i.e. the intergovernmental and supranational components) of the procedure referred to in Article 259 TFEU, see G. Butler, The Court of Justice as an Inter-State Court, cit.; G. Íñiguez, The Enemy Within?, cit., p. 1118 ff.

29 L. Fumagalli, Art. 259 TFUE, in F. Pocar, M.C. Baruffi (eds.), Commentario breve ai Trattati dell’Unione europea, 2^nd ed., Padua, 2014, p. 1285 ff., p. 1286.

30 See in this regard: the joint applications by the Netherlands and Canada against Syria for violation by the latter of its obligations under the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment: Joint Applications Instituting Proceedings Filed in the Registry of the Court on 8 June 2023 (Canada and the Netherlands v. Syrian Arab Republic), para. 7; the application filed by South Africa against Israel for violation of its obligations under the Convention on the Prevention and Punishment of the Crime of Genocide in the Gaza Strip: Application Instituting Proceedings Containing a Request for the Indication of Provisional Measures Filed in the Registry of the Court on 29 December 2023 (South Africa v. Israel), para. 5. The following countries have filed applications to intervene in the latter proceedings (in chronological order): Colombia, Libya, Mexico, Palestine, Spain, Turkey, Chile, the Maldives, Bolivia, Ireland, Cuba, Belize, Brazil, the Comoros Islands and Belgium. On this subject, see M.I. Papa, Litigating Collective Obligations before the International Court of Justice; Progress, Challenges and Prospects, in The Law and Practice of International Courts & Tribunals, 2024, p. 36 ff.

31 International Court of Justice, 5 February 1970, Barcelona Traction, Light and Power Company, Limited, in I.C.J. Reports 1970, p. 3 ff., para. 33.

32 See also H. Runcheva Tasev, M. Apostolovska-Stepanoska, L. Ognjanoska, The Potential of Article 259 TFEU as a Tool for Upholding the Mutual Trust in the EU, in EU and Comparative Law Issues and Challenges Series, 2022, p. 625 ff, p. 641.

33 Considering also the discretion that the Court may exercise in infringement proceedings. See on this, C. Burelli, La discrezionalità della Commissione europea nelle procedure di infrazione, Turin, 2024.

34 Supra, footnote 10. Cf. also K. Lenaerts, K. Gutman, J.T. Nowak, EU Procedural Law, 2^nd ed., Oxford, 2023, p. 198, footnote 133.

35 Court of Justice, 4 October 1979, Case 141/78, France v. United Kingdom, ECLI:EU:C:1979:225; 18 June 2019, Case C-591/17, Republic of Austria v. Federal Republic of Germany, ECLI:EU:C:2019:504; 30 April 2024, Case C-822/21, Republic of Latvia v. Kingdom of Sweden, ECLI:EU:C:2024:373.