A month after an appeals court ruled against same-sex marriage, the city and about a dozen homosexual couples have filed an appeal to the California Supreme Court.

Gay marriage advocates hope to overturn the ruling that said limiting marriage to a man and a woman does not violate the constitutional rights of gays and lesbians.

If the high court takes the case, a decision on same-sex marriage is likely a year or more away. The justices have 90 days to announce their intentions.

In October, the 1st District Court of Appeal ruled in a 2-1 vote that, among other things, it was not the judiciary's role to define marriage — since 61 percent of California voters in 2000 declared marriage as a union between a man and a woman under Proposition 22.

The appeals court also ruled that the state's existing marriage laws do not discriminate because gays and lesbians get most all the rights of marriage the state confers to heterosexual married couples.

The seven-member Supreme Court is not obligated to review the appellate court's decision, which overturned an earlier decision by a San Francisco trial judge. If it does not, the ruling stands.

San Francisco Mayor Gavin Newsom put the marriage debate in the national spotlight by allowing same-sex couples to get married at City Hall in 2004. California's justices halted the wedding spree and voided the 4,037 marriage licenses while sidestepping the core constitutional question, ruling the mayor did not have authority to make marriage law.

Since 2004, when Massachusetts became the first state to legalize gay marriage, advocates have seen California as one of their best hopes for expanding the marriage movement.