Singing sensation Lady Gaga threw the full weight of her stardom Monday behind efforts to repeal a US ban on gays serving openly in the military, decrying it as "against all that we stand for as Americans."

The pop provocateur electrified a crowd of several hundred in a park here in the northeast US state of Maine, home to two Republican US senators who Lady Gaga and other gay rights activists hope will break with their party and support ending the ban.

The openly bisexual singer -- an icon in the gay community -- has urged senators to vote to repeal "Don't Ask, Don't Tell," a law that requires gay military personnel to hide their sexual orientation or face dismissal.

"Equality is the prime rib of America," she told the crowd. "But because I'm gay I don't get to enjoy the greatest cut of meat my country has to offer."

She appeared to be alluding to the explosively controversial "meat dress" that she wore to the MTV Music Awards earlier this month -- a provocation she seemed to confirm was an effort to draw attention to the inequality of the 1993 rule that requires gays to disclose their sexual orientation or face dismissal.

"I'm here because Don't Ask, Don't Tell is wrong, it's unjust, and fundamentally it is against all that we stand for as Americans," she said to rapturous applause.

Dismissing what she called the use of homophobia as a defense in the argument that gays should not openly serve, she proposed turning the tables on soldiers who claim they can't perform their duties adequately alongside a gay colleague.

"Doesn't it seem to be that Don't Ask, Don't Tell is backwards?" she asked, observing that gay soldiers who "hold and harbor no hatred, no prejudice, no phobia, are sent home" while "homophobic" troops remain on the job.

"If you are not honorable enough to fight without prejudice, go home!" she said in her fiery 20-minute speech before hugging veterans who had been dismissed by the US military because their sexual orientation was disclosed.

The Senate was set to vote Tuesday afternoon on a bill that includes a repeal of the ban, but Arizona Senator John McCain, the Republican who lost to Barack Obama in 2008, is expected to block the vote with a move called a filibuster.

The Maine lawmakers Lady Gaga is lobbying with her rally, Senators Olympia Snow and Susan Collins, have not said how they will vote on the issue.

Kevin Kelly, a spokesman for Collins, said the senator "is undecided. She has encouraged Senator (Harry) Reid to work with Republican leaders to come up with an agreement to allow for Republican amendments."

A "yes" vote by at least 60 of the Senate's 100 members would end the filibuster and allow a full vote on the bill to proceed.

Obama's Defense Secretary Robert Gates and Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, both backed the repeal this year, and said a Pentagon study due at the end of 2010 would help guide the new rules for military service.

Lady Gaga singled out McCain for his filibuster, and in a message to her 6.4 million fans on Twitter urged fans to call their senators to end the filibuster.

McCain, a former naval officer with strong ties to the military, said he was not opposed to ending the ban, but did not want it repealed before a thorough study is conducted on its impact on military effectiveness and morale.

On Monday, he told reporters, "I encourage the debate and discussion," even giving a nod to Lady Gaga.

"I'm confident that all the young people who admire her will read about this issue and study it and I'm confident that we will have more support," McCain said.

The US House of Representatives in May passed its version of the bill with a provision to repeal the controversial measure, with Collins voting in favor.

This video was published to YouTube on Sept. 20, 2010, originally broadcast by CNN.

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