Roughly two-thirds of the money raised by a coalition of gay rights groups campaigning to legalize gay marriage in New York came from a group of conservative donors to the Republican Party, the New York Times reported.

About $1 million in donations delivered in recent weeks to the nascent group New Yorkers United for Marriage came from wealthy donors known for bankrolling right-leaning candidates and causes, including Elliott Management Corp. CEO Paul E. Singer, described by the paper as “one of the most generous Republican donors in the country.”

Singer's promotion of marriage equality first came to the forefront last year when he hosted a New York fundraiser for the American Foundation for Equal Rights (AFER), the group created specifically to support a challenge to California's gay marriage ban, Proposition 8.

He's also among the 24 prominent business leaders who last month signed onto a letter urging lawmakers to legalize the institution in the Empire State.

Other bankrollers to the cause are Steven A. Cohen, who runs SAC Capital Advisers, and AQR Capital Management's Clifford S. Asness, a self-described libertarian who has previously praised the Tea Party.

“This is an issue of basic freedom,” Asness said.

“We believe in social justice for all Americans,” Cohen told the paper.

Singer, who serves as chairman of the Manhattan Institute, a conservative research group, has a married gay son, who lives in Massachusetts, where gay marriage was legalized in 2005, and, according to the paper, is deeply involved in the fund-raising effort. He's donated nearly half-a-million of his own money and has personally raised another $500,000 from donors.

New York City Mayor Michael R. Bloomberg, a Republican turned independent and philanthropist, is also deeply involved it the lobbying effort, and has given at least $100,000 of his own money. He's also hosted fund-raisers and recorded a video ad urging New Yorkers to support the cause.

The pressure from inside the GOP tent to support marriage equality could affect a key vote in the Republican-controlled Senate, where a gay marriage bill died in 2009 when Democrats controlled the chamber with no Republican support.

Gay marriage opponents, led by New York state Senator Ruben Diaz Sr., on Sunday will hold a rally against the proposed legislation, and have launched a campaign that characterizes the effort as an impending attack.