Even as voters in California banned same-sex marriage in a tight referendum, Tuesday's election opened the door for the same debate in New York.

The pending shift in state Senate control away from Republicans removes one clear obstacle to legalising gay marriage in New York, though opponents aren't conceding anything yet and advocates say they have work to do.

Democrats won a narrow majority in New York's Senate, where Republicans have buried legislation to start issuing marriage licenses regardless of gender.

A Senate power shift was not a sure thing because four Democrats were considering an alliance with the Republicans, which could swing the 32-30 majority back to Republicans.

"The only chance we had for meaningful debate or consideration of these issues in the state Senate was with a new Senate leadership," said Alan Van Capelle, executive director of the Empire State Pride Agenda, New York's largest gay rights advocacy group.

He added that no bills have passed in New York without some votes from members of both parties.

The Reverend Duane Motley, founder of New Yorkers for Constitutional Freedoms, which opposes gay marriage, said they knew that with Republicans in control of the Senate that legislation to legalise it "was not going to come up."

With Democrats in control, he said party members will be pushing for it, but he questioned whether they have the votes.

"I think there's at least four or five Democrats who wouldn't support it," said Motley, who said his group represents more than 2000 evangelical churches and 500 other Christian organisations statewide.

He believes the Republican senators will remain opposed.

The Democrat-controlled state Assembly in 2007 passed legislation to legalise gay marriage 85-61, a measure backed by then-Governer Eliot Spitzer.

It's not clear yet if political support for gay marriage will be affected by Tuesday's vote in California, where 52 percent of those voting favored the ban versus 48 percent against. It was the first time a state took away gay marriage after it had been legalised.

Amendments to ban gay marriage also were approved in Arizona and Florida.

A Quinnipiac poll in June showed New Yorkers split over gay marriage, with 42 percent saying same-sex couples should be allowed to legally marry, 31 percent saying they should be allowed to form civil unions but not marry, and 21 percent saying there should be no legal recognition of same-sex unions.

Sapa