NEW YORK — As the question of same-gender marriage in New York goes down to the wire at Albany, experts on the legal impact of the changes being sought are warning that religious exemptions in Governor Cuomo’s bill have fallen far short of what the religious community had been praying for.

One letter, sent to Senator Greg Ball from a law professor at Washington and Lee University at Virginia, notes that Mr. Cuomo’s bill offers “far more protections than the failed 2009 bill,” a reference to a measure that two years ago passed the assembly but stalled in the upper chamber at Albany.

But the letter, from Robin Fretwell Wilson, warns that “real protection missing” in the measure involves potential penalties for businesses and individuals at the hand of the government for failing to lay aside their religious objections and provide services for gay marriages . The letter provides, in a detailed, provision-by-provision comparison with what it calls “core protections elsewhere” and shows the proposed measure to be silent on key elements.

Professor Wilson’s letter is significant not only because of her distinction in the field but because the issues she is raising are the point at which a number of senators are on tenterhooks. Ms. Wilson is one of six law professors or experts who signed a May 17 letter to the majority leader of the Senate, Dean Skelos, warning that “conflicts between same-sex marriage and religious conscience will be both certain and considerable if adequate protections are not provided.”

The May 17 letter was signed by Ms. Wilson and Carl Esbeck of the University of Missouri Law School, Marc D. Stern, a leading advocate of religious liberty, Thomas Berg, a professor at University of St. Thomas School of Law at Minnesota, Richard W. Garnett of University of Notre Dame Law School, and Edward McGlynn Gaffney JHr., a professor of law at Valparaiso University.

The letter warns that “without adequate safeguards, many religious individuals will be forced to engage in conduct that violates their deepest religious belies, and religious organizations will be constrained in crucial aspects of their religious exercise.” They urged the legislature in New York to “take the time and the care to ensure that the legalization of same-sex marriage does not restrict the inalienable right of religious liberty.”

Such a warning comes as both Mr. Cuomo and Mayor Bloomberg have been orchestrating what the Archbishop of New York, Timothy Dolan, has called a stampede to get the legislation passed this session. The religious community has for several years been seeking a formal hearing at which these issues could be addressed, but it was curtly spurned in the Assembly by the speaker, Sheldon Silver, in 2007, and no hearings have been held in either chamber since then.