Slovakia’s parliament amended its constitution Friday to state that all citizens are either male or female, limit adoption to married heterosexual couples and ban surrogacy.

Several human rights organizations, including Amnesty International and the Venice Commission, have raised concerns — particularly over an article in the amendment that grants Slovakia’s national law precedence over EU law in “cultural and ethical matters.”

“In fundamental key value questions, national law must take precedence and have priority over international agreements to which the Slovak Republic is bound. That’s common sense,” said Slovak Prime Minister Robert Fico at a press conference Thursday.

Amnesty International said, it’s “a dark day for Slovakia” in a press release.

European Democracy and Justice Commissioner Michael McGrath said in January, when the proposal to amend the constitution was announced, that “the primacy of EU law … is nonnegotiable.”

Since Fico returned to power in October 2023, Slovakia has cracked down on independent media and judiciary, along with LGBTQ+ and artists’ rights, following an “illiberal” playbook sketched out by Hungary.

The controversial amendment, which will come into force in November, was surprisingly approved by a narrow margin.

The government coalition, which initially lacked support to pass the change, gained 13 votes from the opposition conservative Christian Democrats and conservative-populist Movement Slovakia.

The European Commission did not immediately respond to a request for comment.