"The importance of motherhood and fatherhood in Slovenian legislation is now in the hands of the citizens," Aleš Primc, the head of the civil initiative, said in a statement. The family law does not respect mothers and fathers and should be rejected, he said.
Outgoing Labour, Family and Social Affairs Minister Ivan Svetlik, whose ministry drafted the law, responded to the filing of signatures by saying that the law opponents were using the referendum to deny some children the right to a safe, carefree and encouraging childhood.
He said he regretted that "the guardians of the Constitution had failed to protect the basic and constitutional rights" but stressed it was now up to the people to protect these rights.
"We call on the citizens not to let their free choice of a family and private life be taken away from them, and to vote for the law," he stated.
In an interview with the STA, Constitutional Court President Ernest Petrič said that by allowing for the possibility of a referendum, the Constitutional Court had not ruled on the contents of the law. On the contrary, the court had to determine whether a rejection of the law in the referendum would lead to an unconstitutional situation, he said.
But if the law is rejected, the current legislation will stay in force, which is not unconstitutional. "In other words, we would have prevented a referendum if the new law would have been passed to do away with an unconstitutional situation," he explained.
Meanwhile, several groups and parliamentary as well as non-parliamentary parties including Positive Slovenia, (PS), the SocDems, the Virant List, the Party for Sustainable Development (TRS), Zares, the LibDems and the SMS - Greens, announced they will join their forces in the referendum campaign.
The group, which also includes the Institute for the Family Law, For Spaces of Freedom, Women's Lobby of Slovenia, the Peace Institute, the For All Families Initiative, the Students' Organisation of the University in Ljubljana and the Liberal Academy, is called the Movement for the Family Law.
The new family law, adopted by the outgoing centre-left government, updates 1976 legislation. Most of the provisions are not controversial: a ban on corporal punishment of children, a children's rights ombudsman and the transfer of decisions on children's rights in custody disputes from social centres to courts.
But the focus of debates, egged on by the Catholic Church, has been on gay couples getting almost the same rights as heterosexual couples. Most notably, that would have allowed gay couples to adopt their partner's children.
The adopted law is a toned down version of the original proposal, as some of the most controversial provisions, including full equalisation of gay and heterosexual marriage, had been thrown out due to protests by conservative groups.