Republican lawmakers are urging Governor Arnold Schwarzenegger to defend California's gay marriage ban, Proposition 8.

Twenty-seven members of the Assembly's Republican caucus wrote to Schwarzenegger asking the governor to appeal a federal ruling that struck down Proposition 8 as unconstitutional.

Schwarzenegger, a Republican, and Attorney General Jerry Brown, a Democrat who is running for governor, refused to defend the law and have said they would not file an appeal.

“It does not matter whether we, the Attorney General, or you supported or opposed Proposition 8, or whether we believe it should or should not be the law of California,” the lawmakers wrote. “The people of the state of California themselves decided this issue on November 4, 2008.”

“The initiative was upheld by the California Supreme Court as a valid exercise of the people's initiative authority under our state Constitution. One elected federal court judge cannot be allowed to void such a decision, let alone do so without recourse to appeal.”

Schwarzenegger is also being pressured to defend the law by the Christian-based legal group Pacific Justice Institute, which filed a lawsuit on Monday in the Third District Court of Appeals in Sacramento to force Schwarzenegger and Brown, as representatives of the state, to file an appeal.

Social conservatives are increasingly worried that they'll lose their case on a technicality.

Proposition 8's sponsor, Protect Marriage, a coalition of social conservative groups that includes the Church of Jesus Christ of Latter-day Saints (the Mormons), the California Catholic Conference and various evangelical churches, intervened to defend the law after the suit's named defendants, Schwarzenegger and Brown, refused.

But doubts have been raised about whether the group has legal standing to appeal the ruling as ordinary citizens.

The Ninth Circuit Court of Appeals in San Francisco has put the decision on hold and scheduled oral arguments for the second week in December.

The state has until September 11 to file an appeal.