In a breathtaking coup, two Democratic New York Senators have sided with Republicans to flip control of the chamber to the GOP, dooming a gay marriage bill waiting for Senate approval to become law.

Whether the gay marriage bill prompted the lawmakers to act remains to be seen. The two Democrats who handed power to the Republicans – Pedro Espada Jr. of the Bronx and Hiram Monserrate of Queens – hold mixed opinions on the legalization of gay marriage in New York.

The new majority voted to appoint Nassau Republican Dean Seklos, a gay marriage opponent, senate majority leader. Democrats decried the manoeuvre as “illegal.”

“This was an illegal and unlawful attempt to gain control of the Senate and reverse the will of the people who voted for a Democratic majority,” ousted Senate Majority Leader Malcolm Smith said.

Republicans controlled the New York Senate for four decades before losing power in November.

The two Democrats were lured by Republicans with plum positions; Espada becomes the state's first Hispanic senate president.

Smith and Seklos both claim to run the chamber.

The new majority – 32 to 30 – is certain to let the clock on gay marriage run out as the legislative session winds to an end.