The dispute eventually reached Poland's Supreme Administrative Court, which referred the matter to the CJEU for a preliminary ruling.

Following the European court's decision, Poland's highest administrative court ruled that transcribing foreign same-sex marriage certificates into Polish registers does not violate the fundamental principles of the Polish legal order.

The implications extend beyond Poland. Slovak politicians, including Progressive Slovakia MP Michal Sabo, former Presidential Office head Metod Spacek and SaS foreign policy expert Ivan Novotny, have already announced efforts to secure similar recognition in Slovakia.

Yet Slovak law defines marriage as a union between a man and a woman, a principle protected at the constitutional level. The attempt to use a European court ruling to achieve what domestic legislation explicitly rejects raises fundamental questions about constitutional sovereignty and democratic legitimacy.

European Rules Require Impartiality

EU law requires CJEU judges to be independent and impartial, avoiding both actual and apparent conflicts of interest.

Article 253 of the Treaty on the Functioning of the European Union states that judges must provide guarantees of complete independence. Members of the court also swear to perform their duties impartially and are expected to avoid situations that could create the appearance of bias.

The difficulty is that several members of the Grand Chamber deciding this case had previously taken public positions on the very issue before them.

The Judge Who Campaigned for Same-Sex Marriage

One of the clearest examples is Judge François Biltgen.

Before joining the CJEU in 2013, Biltgen spent years in Luxembourg politics, serving as a member of parliament, justice minister and holder of several other ministerial posts.

As justice minister, he actively promoted legislation introducing same-sex marriage. In 2010, he helped advance reforms allowing same-sex couples to marry and adopt children. He later stated publicly that he had “always been in favor of same-sex marriage” and had sought to enshrine it in law during his political career.

The same individual later sat in judgment on a case concerning the recognition of same-sex marriages throughout the European Union. It is difficult to argue that such circumstances do not raise legitimate questions regarding impartiality.

From Political Advocacy to Judicial Decision-Making

Another member of the chamber, Eugene Regan, served as a senator for Ireland's Fine Gael party between 2007 and 2011.

Fine Gael presents itself as a progressive reform movement and counts the introduction of “marriage equality” among its political achievements. Long before Ireland legalized same-sex marriage, the party supported civil partnerships and broader recognition of same-sex relationships.

Again, the issue is not whether those political goals were right or wrong. The issue is whether a former politician associated with a party that actively pursued such reforms should participate in a landmark judgment addressing precisely the same question.

A Broader Pattern

The concerns do not end with Biltgen and Regan.

Other judges involved in the ruling have backgrounds in academic projects, legal initiatives, NGOs and public institutions that promote liberal interpretations of European law or support progressive social reforms. Some have participated in projects focused on gender equality, minority rights or the expansion of legal recognition for same-sex relationships.

Taken individually, such connections may appear minor. Collectively, however, they create the impression of a court whose members overwhelmingly share a similar ideological outlook on contested social questions.

Why This Matters

None of this proves that the judges deliberately ruled in a particular way. There is no legal finding to that effect, nor is one likely ever to exist.

The problem is different. European standards require not only actual impartiality but also the appearance of impartiality. A reasonable observer must be able to trust that judges have no prior commitments that could influence their judgment.

That standard becomes difficult to satisfy when former politicians who publicly campaigned for same-sex marriage later participate in decisions that effectively expand its recognition across the European Union.

No Practical Way to Challenge the Decision

Even if concerns about judicial bias were taken seriously, there is no meaningful mechanism for revisiting such a judgment.

The Grand Chamber effectively functions as the court of last resort. Revision is possible only if genuinely new facts emerge, and the judges' political histories are not new facts. They have simply been ignored.

The ruling therefore remains binding, and member states must comply with obligations created through judicial interpretation rather than democratic consent.

This particular judgment, which some politicians now invoke against constitutional provisions in countries such as Slovakia, was issued by a chamber that included former politicians and individuals closely connected to ideological and activist causes aligned with the outcome of the case.

That is not what impartial justice respecting national sovereignty looks like. It is what happens when political questions are transferred from elected institutions to courts whose members increasingly act as lawmakers in judicial robes.