BATON ROUGE, La.  —  A judge on Monday refused to block a Sept. 18 statewide vote on a proposed constitutional ban on same-sex marriages (search).

Amendment opponents said they would appeal. Time is critical because the secretary of state is facing a deadline this week to get ballots to the printer.

Louisiana already has a law stating that marriage can be only between a man and woman, but supporters of the amendment want to protect that law in the Constitution.

A group called Forum for Equality (search) sued, arguing the ban would violate the Louisiana Constitution's guarantee of individuals' rights to enter into contracts and own property together.

Judge Michael Caldwell heard arguments Monday and refused to order the amendment removed from the ballot. He ruled that under Louisiana law such a challenge can be made only after an election is held.

On Friday, another judge filed a temporary order blocking the vote because Sept. 18 is not a statewide election date, as the Constitution requires. However, he suspended his order so the state can appeal directly to the Louisiana Supreme Court. That judge scheduled a trial for Friday on whether to make his order permanent.