Republican vice presidential nominee Sarah Palin says she supports a constitutional amendment banning gay marriage - a break with her presidential running mate John McCain who has said he believes states should be left to define what marriage is.

The Alaska governor said in an interview with Christian Broadcasting Network: "I have voted along with the vast majority of Alaskans who had the opportunity to vote to amend our Constitution defining marriage as between one man and one woman. I wish on a federal level that's where we would go. I don't support gay marriage."

"I'm not gonna be up there judging individuals, sitting in the seat of judgment telling them what they can and can't do, should or shouldn't do. But I certainly can express my own opinion here and take actions that I believe would be best for traditional marriage and that's casting my votes and speaking up for traditional marriage. That instrument that - it's the foundation of our society, is that strong family and that's based on that traditional definition of marriage..."

In 1998 she voted for a state amendment banning same sex marriage in Alaska.

McCain, an Arizona senator, says he supports a ballot initiative in his state this year that would ban gay marriage although he opposes a federal marriage amendment, saying it would usurp states' authority on such matters.

Democratic vice-presidential candidate Joseph Biden who appeared on the "Ellen" show on Monday when asked said he would vote against a ballot measure that seeks to ban gay marriage if he lived in California.

He called Proposition 8 "regressive" and "unfair" and added that he and running mate Barack Obama opposed a similar initiative nationally.

Meanwhile talk show host Ellen DeGeneres who married actress Portia De Rossi in August has reportedly spent US$100,000 to buy TV airtime for a 30-second public service announcement (PSA) she had filmed to urge California citizens to vote against Proposition 8 which seeks to outlaw same sex marriage.

Her move follows actor Brad Pitt and filmmaker Steven Spielberg with his wife Kate Capshaw also supported the campaign to keep gay marriages legal in California by donating US$100,000 each.

Usnews.com reported that as of last week same-sex marriage proponents are struggling to keep pace both in donations and on the air, raising less than US$20 million, while Protect Marriage - a group leading the campaign in support of the ban - had raised more than US$26 million from more than 64,000 donors, many of them from outside the state.

Other notable gay and lesbian donors include billionaire Jon Stryker (over US$500,000), Dreamworks Studio CEO David Geffen (US$100,000), Grey's Anatomy actor T.R. Knight (US$100,000), personal finance guru Suze Orman (US$10,000), Milk director Gus Van Sant (US$2,500), Star Trek veteran George Takei (US$2,500). Even infamous celebrity blogger Perez Hilton managed US$1000, according to Gaywired.

Transcript of Ellen DeGeneres's public service announcement:
Hi, I'm Ellen DeGeneres. I got to do something this year I never thought I'd ever be able to do: I got married. It was the happiest day of my life. There are people out there raising millions of dollars to try and take that right away from me. You've seen their ads on TV. They're twisting the truth, and they're trying to scare you. I believe in fairness. I believe in compassion. I believe in equality for all people. Proposition 8 does not. Please, please, vote no on Prop. 8.