Laws limiting marriage to a man and a woman do not violate California's constitution, but neither would a law allowing same-sex couples to marry, according to the state attorney general.

Attorney General Bill Lockyer (search) issued the opinion Friday, a long-awaited response to a pair of lawsuits out of San Francisco challenging laws that ban gay marriage.

"Rights are considered fundamental only if they are deeply rooted and firmly entrenched in our state's history and tradition," Lockyer said. "There is simply no deeply rooted tradition of same-sex marriage in California or in any other state."

But Lockyer also said in a statement, "Committed and loving relationships between two individuals deserve recognition under California law.

"The obligations and benefits that attend such relationships form the cornerstone of nurturing families and a stable society," he added.

The two lawsuits were filed in March by the city of San Francisco and gay rights advocates after the California Supreme Court (search) ordered city officials to stop issuing marriage licenses to gay and lesbian couples.

The lawsuits claim California's marriage laws violate the state constitution's anti-discrimination provisions. Those are the same arguments that persuaded Massachusetts' highest court to legalize gay marriage there earlier this year.

Lockyer denied there has been any violation of California's constitution, while at the same time saying the state Legislature has taken significant steps toward granting full spousal benefits to gay couples who register as domestic partners.

"California's effort to find a balance between affording rights and benefits to same-sex couples, while maintaining a common understanding of marriage, does not run up against the constitution," he wrote in a 37-page brief.

Supporters and opponents of gay marriage were eager to see how Lockyer, a Democrat who has expressed interest in running for governor in 2006, planned to navigate the politically volatile question.

Jon Davidson, who is helping represent the 12 suing couples as a senior attorney with Lambda Legal Defense and Education Fund (search), said that in his view, Lockyer "is putting up a vigorous defense."

"It looks like the attorney general is making the strongest case the state can make to defend the restriction against same-sex couples from marrying given the current state of California law," Davidson said. "I am disappointed about his view that not allowing same-sex couples to marry is not discrimination against gay people."

By taking the position that any change in marriage eligibility criteria must come from the Legislature, however, Lockyer essentially advanced the same legal strategy that Massachusetts Attorney General Thomas Reilly (search), a fellow Democrat, unsuccessfully used to prevent gay couples from being able to wed in his state.