BOSTON, May 23 — An effort to end New Hampshire’s status as the only state in the country without a law requiring adults to wear seat belts suffered a setback on Wednesday, when the State Senate transportation committee recommended that it not pass.

By a vote of 3 to 2, the committee recommended that the Senate reject the bill when it comes up for vote sometime in the next two weeks. The bill passed the House 153 to 140 in April.

Bills requiring seat belt use have failed in New Hampshire for years, most recently in 2006. But a coalition of lawmakers, law enforcement organizations and medical groups banded together this year to push the bill before the legislature, which is controlled by Democrats for the first time since 1874.

“We feel it’s the most cost-effective and simplest means of cutting deaths and serious injuries in highway collisions,” said Earl Sweeney, assistant commissioner of the New Hampshire Safety Department, which has endorsed the bill. “It seems like a simple act, to fasten a seat belt.”