BUCHAREST, Romania (AP) — Romania's top court has given a green light to a referendum that could change the constitution to explicitly state that marriage is a union between a man and a woman.

The Constitutional Court decided Monday in a 7-2 vote that there is no legal impediment for the Oct. 7 referendum.

Senators approved the referendum last week, after 3 million Romanians signed a petition demanding a constitutional amendment redefining marriage, which is currently defined as a union between "spouses."

Some lawmakers in this socially conservative Eastern European state argue that the constitution should be changed on religious grounds.

Groups advocating for equality for same-sex couples have condemned the referendum, which needs a turnout of 30 percent to be valid.

Romania doesn't recognize same-sex marriage or offer legal protection to same-sex couples.