A bill authorizing civil unions for gays cleared its last hurdle today in New Hampshire, the first state to embrace same-sex unions without a court order or the threat of one.

The Senate passed the bill 14-10 on straight party lines, Democrats in favor, Republicans against.

“To me this legislation is a credit to our state. We’re making this move not because some court someplace is telling us that we must,” said Democratic Sen. Joe Foster of Nashua. “We do so today because it is the right thing to do.”

The bill goes to Gov. John Lynch, who announced last week he will sign it.

“This legislation is a matter of conscience, fairness and of preventing discrimination,” said Lynch spokesman Colin Manning. “It is in keeping with New Hampshire’s proud tradition of preventing discrimination.”

The bill’s success is an about-face from two years ago, when a study panel recommended giving no meaningful consideration to extending legal recognition to gay couples. That panel, staffed mostly by supporters of a ban on gay marriage, concluded that homosexuality is a choice and endorsed a constitutional amendment to limit marriage to unions between a man and a woman.

Democrats won control of the Legislature last fall for the first time in more than a century.

Sponsors of the civil unions bill called it a door to marriage in all aspects but name. Republicans seized on that remark, saying civil unions would lead to a collapse of traditional values.

“Let’s just call it what it really is, no sugar-coating, no b.s. This creates same-sex marriage. There is no right to marriage in either the New Hampshire Constitution or the federal Constitution. Rather it’s natural law that defines marriage,” said Republican Sen. Robert Letourneau, of Derry.

He added, “We don’t let blind people drive or felons vote, all for good and obvious reasons.”

Civil unions, he said, “aims for a definition closer to open marriage where mutual fidelity is not expected.”

New Hampshire will join New Jersey, Connecticut and neighboring Vermont in offering civil unions beginning Jan. 1. Vermont and Massachusetts were the first states to offer civil unions and marriage, respectively, to same sex couples in 2000 and 2004. Both moves followed court decisions.

New Jersey’s civil unions also followed a court ruling. In Connecticut, a lawsuit challenging the state’s marriage law was pending when lawmakers passed civil unions.

There are no active court challenges of New Hampshire’s marriage law. Two years in a row, lawmakers defeated proposed constitutional bans on same-sex marriage.

Washington, Maine, California, New York and Washington D.C., recognize domestic partnerships. New York Gov. Eliot Spitzer this week pledged to introduce gay marriage legislation in the next few weeks.