Cupriak-Trojan & Trojan v. Wojewoda Mazowiecki

Written by Aryan Patel

In October 2025, the Cupriak-Trojan and Trojan v Wojewoda Mazowiecki case, which occurred because a Polish same-sex couple got married in Germany but then had their marriage rejected by Poland, who does not allow same-sex marriage, was a landmark case for the European Union. It resulted in the EU upholding the couple’s marriage, as the denial of the marriage was deemed to be against respecting family and private life as well as discrimination based on sexual orientation, both of which are in the Charter of Fundamental Rights of the EU.

This case is a great example of how the EU becomes the highest authority for these states, therefore undermining national sovereignty. In this scenario, because of the EU, Poland is forced to accept the verdict, going directly against their laws. While this case is focused on same-sex marriages, it also brings up a larger problem for other fields where Member States have ceded sovereignty to the EU, such as the single market, economies, environment, transportation, and other fields mentioned in the Charter. 

Britain has already left the EU, due to many concerns over immigration, healthcare issue and, most notably, the right to control their laws. In the Factortame case, Britain was denied the right to institute the Merchant Shipping Act of 1988, which would require vessels to register to fish in the UK. This result was because of EU authority taking precedence over British authority. The Factortame case is one of many cases that rejected Britain’s authority, and helped drive the UK’s leaving the EU.

Whether it be over same-sex marriages or registration for fishing, there are numerous ways and numerous laws in which Member States’ authority and laws can be denied in favor of the EU’s authority. Yes, Member States gain massive benefits from joining the EU, but what do they lose from being part of the EU? And are the benefits really worth sacrificing part of their authority? 

Works Cited

Primacy of EU Law (Precedence, Supremacy). European Union, european-union.europa.eu/index_en. Accessed 21 Jan. 2026.

Twelves, Katie Ann. Parliamentary Sovereignty and EU Membership: Did Brexit Regain Parliament's Sovereignty? 31 Oct. 2025. The Cambridge Journal of Law, Politics, and Art. Accessed 21 Jan. 2026.

"We Welcome the EU's Top Court Landmark Judgment: Member States Must Recognise Same-Sex Marriages from Other EU Countries." ILGA Europe. ILGA Europe, www.ilga-europe.org/news/we-welcome-the-eus-top-court-landmark-judgment-member-states-must-recognise-same-sex-marriages-from-other-eu-countries/. Accessed 21 Jan. 2026.