The Louisiana Supreme Court on Thursday refused to take up legal challenges aimed at keeping a proposed constitutional ban on gay marriages and civil unions off the Sept. 18 ballot.

The high court refused to hear the appeals of three lawsuits but left open the possibility of challenging the amendment -- if it passes -- after the election.

"The court may yet have to address this constitutional question in a post-election challenge," Chief Justice Pascal F. Calogero Jr. wrote.

Three separate lawsuits had been filed on behalf of a group called Forum for Equality, arguing that the Defense of Marriage amendment is unconstitutional because it would deprive unmarried couples -- gay or straight -- of the right to enter into certain contracts and own property together. Supporters of the ban disagree.

The amendment, passed by state lawmakers this year, would also ban state officials and courts from recognizing out-of-state marriages and civil unions between homosexuals.

The legal battle had focused on technical arguments, including whether any election can be challenged before it takes place and whether the amendment illegally promotes more than one objective.

The court gave no reason for its unanimous rejection of the suits.

But Calogero and Justice John L. Weimer wrote in notes that they agreed with lower courts' opinions that the suits were "premature" because state law allows an election challenge only after the vote.

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.