Slovakia put a two sex rule in its constitution by 90 votes, and Brussels opened a case

Slovakia is now the second European Union member state to write a binary definition of sex into its constitution. On 26 September 2025 the National Council of the Slovak Republic adopted a constitutional amendment, published as Constitutional Act 255/2025 Z. z. amending the Constitution No. 460/1992 Coll., which took effect on 1 November 2025. It passed with 90 votes, exactly the three fifths of the 150 seat chamber that a constitutional change requires. PBS NewsHour reported that twelve conservative opposition members joined Prime Minister Robert Fico's coalition to reach the threshold.

The text is short and specific. A new Article 52a reads that the Slovak Republic recognises only the biologically determined sexes of male and female. A new paragraph in Article 41 provides that the parents of a child are the mother and the father, that the mother is a woman and the father is a man. Article 15 gains a prohibition on any agreement to give birth to a child for another, which is a constitutional ban on surrogacy. Article 41 restricts adoption of a minor to spouses, with a court able to permit a single person to adopt by exception, and makes education about intimate life and sexual behaviour conditional on the consent of a legal representative. Article 36 gains a guarantee of equality between men and women in remuneration for work. Article 7 declares that Slovakia retains its sovereignty in matters of national identity, described as fundamental cultural and ethical issues, and that nothing in the constitution may be read as consent to transfer the exercise of rights in those matters.

The Council of Europe's Venice Commission had already examined the draft. Its urgent opinion, CDL-AD(2025)040, Opinion No. 1255/2025, was issued on 24 September 2025 at the request of the chair of the Parliamentary Assembly's Monitoring Committee, and endorsed at the Commission's 144th plenary session in Venice on 9 and 10 October 2025. The Commission recommended deleting the words "biologically determined" from Article 52a and developing a detailed law providing expeditious, transparent and accessible procedures for changing the registered sex marker of transgender people. Parliament voted two days after the opinion was issued and kept the phrase.

The opinion is not a simple condemnation, and its own record contains a contradiction worth reporting rather than resolving. At paragraph 59 the Commission notes that during meetings in Bratislava on 21 and 22 August 2025 the Slovak authorities said that in case of transition the persons concerned would be treated as their new gender. At paragraph 65 it records the same authorities saying that under Slovak law, without a biologically changed gender, a person remains the gender assigned to them at birth. The Commission's own reading, at paragraph 61, is that the provision as worded would imply that transgender, intersex and non binary people cannot obtain legal recognition of a transition in official documents. The Commission also accepted that recognition of a third or neutral sex falls within Slovakia's margin of appreciation, citing the European Court of Human Rights judgment in Y v. France of 2023, while insisting that a strict binary in the constitution cannot justify discrimination in later legislation or state measures.

The sovereignty clause, not the sex clause, is what moved Brussels. JURIST reported that on 21 November 2025 the European Commission opened an infringement procedure, arguing that the amendment offends the primacy, autonomy, effectiveness and uniform application of Union law, and that the exercise of national competence cannot circumvent compliance with fundamental principles of Union law. Slovakia was given two months to reply. If the answer does not satisfy the Commission, the next steps are a reasoned opinion and then referral to the Court of Justice.

Civil society reaction was immediate. Amnesty International called the vote devastating on the day it happened and said the amendments put the constitution in direct contradiction with international law. A joint open letter dated 16 October 2025, published by Amnesty International's European Institutions Office, pressed the point with reference to statements by the Venice Commission, United Nations special rapporteurs and the EU Fundamental Rights Agency.

What is not yet known is how the two readings the Slovak authorities gave the Venice Commission will be reconciled in practice, whether any procedure for changing a sex marker survives, and whether the infringement case reaches Luxembourg. No court has yet ruled on Article 52a.