On 7 October 2021, the latest judgment by the Polish Constitutional Tribunal in the case K 3/21 strikes the European Union like thunder. Poland’s constitution is declared supreme to international agreements ratified by Poland, including the EU Treaties. Such conclusion entails that the Polish Constitutional Tribunal reserves the right to assess the conformity of EU law with the Polish Constitution, breaking thus the EU legal order. The news is quickly relayed across the Union and branded as a “legal Polexit”. The following week, Mateusz Morawiecki, the Polish Prime Minister, declared that Poland had no desire to leave the EU, although he is at the origin of the trouble.
Mr. Morawiecki lodged an application to the Polish Constitutional Tribunal to assess the conformity of certain provisions of the Treaty on European Union (TEU) with the Polish Constitution. The Tribunal started from the premise that Poland is a sovereign and democratic State. It concedes however, that under the EU Treaties the country passed on its sovereignty to the EU but on the condition that the Union respects the national and constitutional identity of the Member States in order to not deny the sovereign and democratic nature of Poland as a State. As a result, the Tribunal sets boundaries to “the process of creating an ever closer Union” as stipulated in Article 1 TEU without declaring that article unconstitutional. To reach the conclusion that the Constitution lays above EU law, the Tribunal relied on one of its judgments (K 18/04) on the relationship between the Polish Constitution and the contents of the Accession Treaty and the EU founding treaties, where the Tribunal stated that the Constitution will not lose its supremacy within the Polish legal order by the mere fact that it is incompatible with Union provisions. The Tribunal then left the resolution of any future conflicts of norms in the hands of the Polish constitutional legislator. Further, the Tribunal also left the possibility for the Polish judiciary to review the constitutionality of the EU Treaties. A possibility seized by the Tribunal sixteen years later.
In both of these judgments (K 18/04 and K 3/21), the Polish Constitutional Tribunal overlooked the seminal case of the Court of Justice of the European Union (CJEU) Costa v ENEL, which affirms the supremacy of EU law over national laws. The CJEU justified its judgment by pointing out that EU law would become meaningless if Member States could unilaterally amend or derogate from EU provisions. The CJEU reiterated that statement regarding the conflict of norms between a national constitution and EU law in the not less famous case Internationale Handelsgesellschaft. Hence the importance of the supremacy of EU law in order to ensure the effectiveness and uniformity of Union law among all Member States.
The Polish Constitutional Tribunal thus upsets the hierarchy of legal norms required by the spirit of the EU Treaties. On that matter, Poland is not innovating. The Tribunal made a reference in its ruling to similar conclusions reached by the German Federal Constitutional Court (GFCC), which on multiple occasions questioned the supremacy of EU law, starting with the famous Solange rulings. The latest violation of the principle of supremacy caused by the GFCC was in May 2020, where the Court ruled that the European Central Bank overstepped its competences when adopting a bond-buying program. By doing so, the GFCC disregarded a CJEU ruling stating the opposite, thereby breaching EU law under Articles 263 and 267 TFEU as the German Court overstepped its competences allocated within the EU legal order. Consequently, the European Commission opened infringement proceedings in June 2021 against Germany for breaching the principle of the supremacy of EU law. The Commission hopes to send a message to all domestic courts in the EU that wishes to question the EU legal order.
However, not all court decisions questioning the supremacy of EU law are relayed in the press. In April 2021, a decision by the French Conseil d’Etat, the highest administrative court, declared the French Constitution supreme to EU law, based on Article 88-1 of the Constitution. Funnily enough, that same article has been consistently interpreted to have the opposite effect by the French Constitutional Court, to reconcile the French Constitution with the principle of supremacy of EU law. And there are many other examples of domestic courts challenging the supremacy of EU law.
The challenge of the principle of supremacy of EU law by the Polish Constitutional Tribunal is therefore not an exception in the EU’s history. But the particularity of that judgment and why it created such a fuss is that Poland’s ruling party has been defiant of EU rules for now several years and the Tribunal’s judgment constitutes an additional strike on the EU’s foundations. Besides, one can wonder whether the Tribunal’s judgment was impartial and independent or rather the expression of a political stance. Because of the concerns over the independence of the Polish judiciary, the country is, for quite a while, the target of the EU for not complying with the rule of law, an EU value. In November 2021, the CJEU found that the intervention of the Polish executive in the adjudication of justice constitutes a breach of the rule of law. The European Court of Human Rights also found that the actions of the executive in the appointment of the Constitutional Tribunal judges resulted in a violation of the right to a fair hearing by a tribunal established by law under Article 6 of the European Convention for Human Rights. Thus, Poland is in breach of the rule of law, which amounted to its exclusion from the European Network of Councils for the Judiciary, whose membership is dependent upon the judiciary’s impartiality and independence.
The Case K 3/21 is not only another challenge of the principle of supremacy like the EU already faced but the result of the intervention of a Polish executive, which dislikes being told what to do by EU politicians, in the judiciary’s affairs leading to a violation of the rule of law. The Constitutional Tribunal’s judgment will face sanctions, as the Commission is determined to ensure the respect of the rule of law across the Union, however long the battle may be.
 Polish Constitutional Tribunal, ‘Press release after the hearing: Assessment of the conformity to the Polish Constitution of selected provisions of the Treaty on European Union’ (Trybunal.gov.pl, 2021) <https://trybunal.gov.pl/en/news/press-releases/after-the-hearing/art/11664-ocena-zgodnosci-z-konstytucja-rp-wybranych-przepisow-traktatu-o-unii-europejskiej> accessed 18 November 2021.
 ‘Polish prime minister accuses opposition of lying about ‘Polexit’’ (Reuters, 12 October 2021).
<https://www.reuters.com/world/europe/polish-prime-minister-accuses-opposition-lying-about-polexit-2021-10-12/> accessed 18 November 2021.
 Polish Constitutional Tribunal, ‘Press release’ (n 1).
 Case K 18/04 Poland’s membership in the European Union (The Accession Treaty) , accessible at <https://trybunal.gov.pl/fileadmin/content/omowienia/K_18_04_GB.pdf> accessed 18 November 2021.
 Case 6/64 Flaminio Costa v E.N.E.L.  ECLI:EU:C:1964:66.
 Case 11/70 Internationale Handelsgesellshaft mbH v Einfuhr- und Vorratsstelle für Getreide und Futtermittel  ECLI:EU:C:1970:114, para 3.
 BVerfG, Judgment of the Second Senate of 5 May 2020 – 2 BvR 859/15.
 Case C-493/17 Heinrich Weiss and Others  ECLI:EU:C:2018:1000; See also Case 314/85 Foto-Frost v Hauptzollamt Lübeck-Ost  ECLI:EU:C:1987:452.
 ‘June infringements package: key decisions’ (European Commission, 9 June 2021) <https://ec.europa.eu/commission/presscorner/detail/en/inf_21_2743> accessed 18 November 2021.
 Conseil d’Etat, Contentieux Nos 393099, 394922, 397844, 397851, 424717, 424718 décision du 21 avril 2021, p 8.
 B. Bonnet, ‘Les rapports entre droit constitutionnel et droit de l’Union européenne, de l’art de l’accommodement raisonnable’ (Conseil Constitutionnel, April 2019) <https://www.conseil-constitutionnel.fr/publications/titre-vii/les-rapports-entre-droit-constitutionnel-et-droit-de-l-union-europeenne-de-l-art-de-l-accommodement> accessed 18 November 2021.
 P. Cleppe, ‘An overview of national top courts challenging the supremacy of EU law’ (Brussels report, 12 October 2021) <https://www.brusselsreport.eu/2021/10/12/an-overview-of-national-top-courts-challenging-the-supremacy-of-eu-law/> accessed 18 November 2021.
 Consolidated Version of the Treaty on European Union  OJ C202/1, art 2.
 Joined Cases C-748/19 to C-754/19 Prokatura Rejonova w Mińsku Mazowieckim  ECLI:EU:C:2021:931.
 Xero Flor w Polsce sp. z o o v Poland, Application no 4907/18 (ECtHR, 7 May 2021).
 ‘ENCJ votes to expel Polish Council for the judiciary (KRS)’ (European Network of Councils for the Judiciary (ENCJ), 28 October 2021) <https://www.encj.eu/node/605> accessed 18 November 2021.
 European Commission, ‘The Rule Of Law Crisis In Poland And The Primacy Of EU Law – President Von Der Leyen At The Eplenary’ (Youtube.com, 19 October 2021) <https://www.youtube.com/watch?v=9CVxFzLmerc> accessed 18 November 2021; ‘Independence of Polish judges: Commission asks European Court of Justice for financial penalties against Poland on the activity of the Disciplinary Chamber’ (European Commission, 7 September 2021) <https://ec.europa.eu/commission/presscorner/detail/en/ip_21_4587> accessed 18 November 2021.