Evangelical, Roman Catholic and Orthodox Jewish leaders, determined to head off momentum for same-sex marriage in Albany, say they are mobilizing an extensive campaign to block legislation that would make New York the sixth state to allow gay men and lesbians to wed.

"Our pastors are fired up by the governor's assault on marriage," said the Rev. Jason J. McGuire, executive director of New Yorkers for Constitutional Freedoms, a lobbying group that represents evangelical churches in the state. "We're already in gear."

Opponents of same-sex marriage have already financed a wave of 500,000 automated calls urging voters to contact undecided lawmakers. And the traditional religious coalition that has fought same-sex marriage in previous legislative sessions now counts among its members Archbishop Timothy M. Dolan, who played only a muted role the last time the issue was debated, in 2009, when he had just been appointed to lead the Catholic Archdiocese of New York.