San Francisco - In a landmark decision the California Supreme Court on Thursday overturned a state ban on gay marriage, making same-sex unions legal in the most populous state in the US. The 4-3 decision is likely to thrust gay marriage back into the political spotlight and potentially make it an important issue in the November general election.
The ruling found that domestic partnerships were not an adequate alternative to marriage.
"Under these circumstances, we cannot find that retention of the traditional definition of marriage constitutes a compelling state interest," the court said in an opinion written by Chief Justice Ron George. "Accordingly, we conclude that to the extent the current California statutory provisions limit marriage to opposite-sex couples, these statutes are unconstitutional."
In a huge victory for gays and lesbians, the court said a gay marriage ban would violate current recognition that "an individual's sexual orientation - like a person's race or gender - does not constitute a legitimate basis upon which to deny or withhold legal rights."
The court's decision could be overturned in November, when Californians are likely to vote on a state constitutional amendment banning same-sex marriages. If voters approve the measure it will supersede Thursday's decision.
Opponents of gay marriage also vowed to fight the ruling. Liberty Counsel said it would ask the justices to stay its effect until after the November election.
"The California Supreme Court has defied logic, undermined the will of the people and weakened our future," said Mathew Staver, Liberty Counsel's founder and chief attorney. "This decision will ignite California voters to amend their state Constitution to protect marriage and prevent judges from wrecking marriage."
Glen Lavy of Alliance Defense Fund, which represented other opponents of same-sex marriage, said, "The court's decision clearly demonstrates that marriage is not ultimately safe from tampering by activists and others in government until the voters have amended the constitution."
The California legislature has twice passed bills legalizing gay marriage, but they were vetoed by Governor Arnold Schwarzenegger, a Republican.
However, he said he would uphold the ruling Thursday. "I respect the court's decision, and as governor, I will uphold its ruling," he said in a statement. "Also, as I have said in the past, I will not support an amendment to the constitution that would overturn this state Supreme Court ruling."
The ruling was also greeted by gay and lesbian activists gathered outside the courthouse in San Francisco.
"As of today, the right to marry is now guaranteed to anyone," said Kate Kendell, executive director of the National Centre for Lesbian Rights. "All I know is that we won."
Prior to the ruling, Massachusetts was the only one of the 50 US states to allow gay marriage, and high courts in New York, Washington and New Jersey had refused to extend marriage rights to gay couples.