In an order issued yesterday, the state's highest court asked lawyers for the city, the state and anti-gay marriage groups to present written arguments on whether the court should declare the marriages valid or void if it rules that San Francisco exceeded its authority in marrying same-sex couples.
Mayor Gavin Newsom ordered the gender-neutral licenses, he said, because the state constitution's equal protection clause supercedes state laws that define marriage as heterosexual.
Legal analysts said yesterday's order indicates that the court is likely to rule against San Francisco.
"If they were upholding the marriages, this question wouldn't arise, so it suggests that they are not going to uphold them," said Stephen Barnett, law professor emeritus at the University of California, Berkeley.
The court issued its one-page order after meeting in closed session during its weekly conference. San Francisco City Attorney Dennis Herrera said the order gave no indication of how the court was leaning.