by Bob Egelko

SAN FRANCISCO - The likelihood of a final California Supreme Court showdown over same-sex marriage increased dramatically Monday when Attorney General Jerry Brown and the pro-Proposition 8 campaign urged the justices to decide whether the voter-approved ballot measure is constitutional.

Both Brown, the state government's top lawyer, and the Protect Marriage campaign organization plan to defend Prop. 8, which would write a ban on same-sex marriage into the state Constitution. In separate filings Monday, the liberal attorney general and the conservative sponsors of the initiative gave similar reasons for asking the court to review lawsuits filed by the measure's opponents.

"There is significant public interest in prompt resolution of the legality of Proposition 8. This court can provide certainty and finality in this matter," Deputy Attorney General Mark Benington said in court papers.

Andrew Pugno, lawyer for Protect Marriage, said, "The people have a right to know as quickly as possible the status of marriage under the California Constitution." He said he was confident that the court will uphold Prop. 8.

However, the Campaign for California Families, another conservative religious organization that supported the measure, asked the court to dismiss the suits without a hearing. The group's lawyer said overturning Prop. 8 "would wreak havoc on the democratic process."

The court could decide at its weekly conference Wednesday whether to accept the suits for review and whether to issue a stay that would block enforcement of Prop. 8 until a ruling is made. A stay would restore authority for gay and lesbian couples to marry, although those marriages - like an estimated 18,000 same-sex weddings performed before the Nov. 4 election - would have an uncertain status until the court cleared up Prop. 8's legality and scope.

Benington argued against a stay, saying any marriages performed in the interim period would be questioned if the court upheld Prop. 8. Brown has promised to defend the validity of the pre-Nov. 4 marriages.

The number of suits challenging Prop. 8 grew to six Monday with filings by women's-rights groups and religious organizations led by the California Council of Churches. Two groups of same-sex couples and local governments led by the city of San Francisco sued Nov. 5 and were joined Friday by civil rights organizations, which said the initiative would set a precedent for eliminating the rights of any minority by popular vote.

All the lawsuits argue that Prop. 8, a state constitutional amendment, violates other provisions of California's Constitution by taking rights away from a historically persecuted minority group and stripping judges of their power to protect that group.

Prop. 8, approved by a 52 percent majority, would overturn the court's May 15 ruling that gave gays and lesbians a constitutional right to marry in California.

The central claim in most of the suits is that Prop. 8 would make such a fundamental change to individual rights and judicial responsibilities that it would amount to a revision of the state Constitution and not merely an amendment. While a constitutional amendment can qualify for the ballot with 694,354 signatures of registered voters, a revision requires a two-thirds legislative vote to reach the ballot.

Opponents of past initiatives have made similar arguments, usually without success. The court upheld the Proposition 13 property tax cut as well as measures reinstating the death penalty, and restricting defendants' rights in criminal cases, ruling that each was an amendment rather than a revision.

But the court struck down provisions in a 1990 crime initiative that would have limited defendants in California to rights recognized by the U.S. Supreme Court, calling it an attack on state courts' authority to exercise their own judgment under the California Constitution.

In 1948, the court removed from the ballot an initiative that would have made wholesale constitutional changes on subjects ranging from pensions to oleomargarine, ruling that it was an invalid revision.

Brown's filing Monday steered clear of the issue, which he presumably will address if the court takes up the cases. The Campaign for California Families, in its brief seeking dismissal of the suits, said Prop. 8 is far less sweeping than the measures the court has invalidated.

The Nov. 4 measure "does not alter the balance of power between the branches of government, nor does it undermine or eliminate fundamental rights," said Mary McAlister, a lawyer for the organization.

All Prop. 8 does, she said, is to enshrine in the state's Constitution "the centuries-old definition of a universal social institution."

The lead case is Strauss vs. Horton, S168047.