California's ban on same-sex marriages is unconstitutional, a San Francisco appeals court has ruled.

旧金山一家上诉法院裁定，加州禁止同性婚姻是违反宪法的。

A statewide referendum on the issue, known as Proposition 8, imposed a bar on gay unions in November 2008 but that was overturned by a court in 2010.

Now a three-judge panel of the 9th US Circuit Court of Appeals has ruled 2-1 that the latter judgement was correct.

Supporters of the ban previously¹ vowed² to challenge the panel's decision if it went against them.

Lawyers for those backing the ban are expected to take the issue to the US Supreme³ Court.

Proposition 8 was a 2008 ballot⁴ measure that amended⁵ the California constitution to state that "only marriage between a man and a woman is valid⁶ or recognised in California".

Two same-sex couples challenged the measure, saying it violated their right to equal protection under the US constitution.

The 2010 ruling overturned the ban, determining it to be a violation⁷ of the civil rights of gays and lesbians.

'No such reason'

The California ban, known as Proposition 8, was passed by voters in 2008.

"Although the Constitution permits communities to enact⁸ most laws they believe to be desirable, it requires that there be at least a legitimate⁹ reason for the passage of a law that treats different classes of people differently," the ruling states.

The panel found "no such reason", the judges said in their ruling.

The 9th Circuit decision also found that there was no evidence that the judge who issued the lower court ruling, Judge Vaughn Walker, was biased¹⁰（有偏见的） , and ruled that he did not have to disclose that he was gay.

That petition was the first time the sexual orientation¹¹ of a judge had been cited as grounds for overturning a court decision.

Judge Walker publicly revealed he was gay after he retired¹².

The 9th Circuit's decision only applies to California, although it has jurisdiction¹³（司法权） in nine states.