“At a bare minimum, the district court exceeded its jurisdiction to the extent its judgment extends beyond the four plaintiffs who were before the court,” lawyers for ProtectMarriage said.

Failing that, the group argued, the court should rule that the Aug. 4 decision affects only the couples named in the suit because it was not filed as a class action on behalf of all gays and lesbians, ProtectMarriage argued.

In written arguments filed Friday night, ProtectMarriage.com, the group that sponsored Proposition 8, urged the U.S. 9th Circuit Court of Appeals to overturn U.S. District Chief Judge Vaughn R. Walker’s ruling against the 2008 ballot measure.

If last month’s ruling overturning Proposition 8 survives, same-sex marriage should be available only to the two homosexual couples who challenged the ballot measure and should remain barred for the rest of the state’s gay and lesbian population, sponsors of the measure told a federal appeals court.

The group suggested such a resolution in the event that the appeals’ court determines that none of the opponents of gay marriage has standing to appeal.

To have standing, a party must show that it has suffered an actual injury. Walker has said there's no evidence to suggest ProtectMarriage would meet that test.

The group told the 9th Circuit that it need not rule on that question because Imperial County, which has been trying to intervene in the case, clearly has standing to defend Proposition 8. Imperial County also filed arguments shortly before midnight Friday asking for standing to appeal.

UC Davis Law Professor Vikram Amar, a constitutional law professor, said he believed ProtectMarriage was legally correct in contending that Walker’s ruling would have to be limited to the four people who filed the lawsuit against Proposition 8.

The lawsuit was brought by a Southern California gay couple and a Berkeley lesbian couple. They are being represented by Theodore Olson and David Boies, legal powerhouses from opposite ends of the political spectrum.

“Under Supreme Court precedent, there's no way a judge can protect plaintiffs other than the named plaintiffs absent a class action,” said Amar, who voted against Proposition 8. He said “Boies and Olson foolishly failed to certify” a class in the case.

In its filing, Imperial County argued that the case should be decided based on the U.S. Constitution, not on a technical question of standing. The county argued that it was entitled to appeal Walker’s order because counties issue marriage licenses.

Gov. Arnold Schwarzenegger and Atty. Gen. Jerry Brown, the named state defendants in the suit, clearly have standing to appeal but have decided not to.

“This case presents the truly extraordinary situation of a constitutional provision without a single governmental defender,” lawyers for Imperial County told the court.

Opponents of Proposition 8 dismissed their adversaries’ arguments.

“The fact remains that Proposition 8 is unconstitutional, as was proven conclusively and unequivocally through a full federal trial, said Chad Griffin, a Los Angeles political strategist who launched the case.

The case is scheduled to be heard by a panel of three 9th Circuit judges in December. The court has put Walker’s ruling on hold pending a decision on the appeal.

-- Maura Dolan