A federal three-judge panel has rejected an appeal by gay rights groups that sought to overturn a federal judge's order forcing them to surrender documents related to Proposition 8, the gay marriage ban narrowly approved by California voters in 2008, Courthouse News Service reported.

Chief US District Judge Vaughn Walker's ruling required pro-gay marriage groups to hand over Proposition 8 campaign materials to defendants in the high-profile trial considering the ban's constitutionality.

Equality California, No on Proposition 8 and the Campaign for Marriage Equality appealed the ruling, but the 9th Circuit said it lacks jurisdiction in the case. The judges said the groups cannot appeal the ruling until they have been held in contempt for failing to comply with it.

In filing its appeal, the groups argued that the documents are confidential internal communications protected by the First Amendment as political speech.

Judge Walker is presiding over the first federal trial to consider the constitutionality of a gay marriage ban. During the January trial, plaintiffs argued that Proposition 8 violates their constitutional rights.

Walker cleared the courtroom after hearing two and a half weeks worth of testimony without issuing a ruling or scheduling closing arguments.

The appeal further delayed the trial's close. The ruling opens up the possibility that closing arguments are closer at hand.

No matter how Walker rules, the decision is widely expected to be appealed all the way to the Supreme Court, whose ruling could affect gay marriage bans throughout the country.