The Constitutional Court of Slovakia has decided that several questions that could limit the rights of lesbian, gay, bisexual and transgender (LGBT*) persons will be opened to a public vote, a move which advocates say is unconstitutional.

It follows a petition initiated by the Alliance for Family, a conservative national organisation that collected more than the 350,000 signatures required to hold a referendum, and which seeks to “preserve marriage and family” and “protect…social values”.

The three questions that will be included in the referendum affirm the definition of marriage as a union between a man and a woman, that only married and heterosexual couples can adopt a child, and that parents be able to opt their children out of subjects such as sexuality education in state-run schools.

Activists, however, question the constitutionality of the referendum, noting that the Slovak Constitution specifically prohibits referenda on issues of fundamental rights and liberties. Commentators say religious and anti-gay organisations have increasingly used referenda since the 1990s to limit the rights of LGBT people.

On the issue of sexuality education, earlier in October the Commissioner for Human Rights at the Council of Europe, Nils Muižnieks, reiterated that “children have the right to receive factual information about sexuality and gender diversity.”