The challenge to the constitutionality of California's gay marriage ban, Proposition 8, returns to court on Monday.

A Ninth U.S. Circuit Court of Appeals three-judge panel will hear oral arguments in the appeal of a lower court's August ruling that found the law violated gay couple's constitutional guarantees to equal protection and due process.

The court will first examine whether, the group that put Proposition 8 on the ballot, and Imperial County have legal authority, or standing, to appeal U.S. District Judge Vaughn R. Walker's ruling. The groups intervened in the case after Governor Arnold Schwarzenegger and governor-elect Jerry Brown, as attorney general, refused to defend the law in court. In his ruling, Walker said he doubted the group's legal standing because they are not directly affected by the law.

Proponents of the law say they'll argue that California voters made a “rational public policy choice” to define marriage as a heterosexual union.

The plaintiffs – a gay couple and a lesbian couple who wish to marry – are being represented by the American Foundation for Equal Rights (AFER), a group formed to support the case.

AFER lawyer David Boies told the Wall Street Journal that he'll argue that the law conflicts with constitutional protections.

Analysts predict the court is likely to find the defendants don't have legal standing because Walker did not order them to do anything. He ordered the state of California to allow gay couples to marry, an order the state is not fighting.

Citing his wife's close ties to the case, defendants last week sought to remove Judge Stephen R. Reinhardt from the case, but he refused to recuse himself.

If appealed to the U.S. Supreme Court, the case could strike down – or fortify – gay marriage bans in 31 states.

The hearing will be broadcast on C-SPAN starting at 10AM.