MONTPELIER, Vt. —  Vermont's Supreme Court has thrown out a challenge to the civil unions law granting gay and lesbian couples the rights and benefits of marriage.

The court turned aside a request by groups of taxpayers, legislators and town clerks that their lawsuit be sent back to Superior Court for a trial. The justices said those groups did not make a strong enough legal argument to warrant a trial.

All five justices signed the order, dated Dec. 26 and released publicly Thursday. They decided the case less than a month after hearing arguments and did it through what's known as an "entry order," a briefer decision that's less formal than a typical Supreme Court ruling.

A lawyer for the groups who sued said they didn't have any other legal recourse.

"Really, I guess, the next option would be for the people of Vermont to go back to the Legislature and get the Legislature to deal with the problem by repealing the law or by enacting more stringent laws prohibiting gambling on the House floor," said Erik Stanley.

There were two primary claims made in the lawsuit. The first claimed the civil unions law was invalid because 14 House members who supported it participated in a betting pool on the outcome of a preliminary House vote.

Town clerks also argued that the law was unconstitutional because it forced them to violate their firmly held religious beliefs that homosexuality is wrong by requiring them to issue civil unions licenses or to appoint an assistant to do it.

The court said it was for the House to decide whether the $1 bets the legislators made constituted a material interest in the outcome of legislation, for which they should have been disqualified.

One lawmaker, Rep. Doran Metzger, R-Milton, complained about the betting but did not lodge a formal complaint, which the court said he could have done under House rules.

"Thus, a legislative procedure was readily available to challenge the civil union vote...," the court wrote. "Whether an adequate objection on this basis was raised by Representative Metzger, or whether the speaker adequately responded to his concerns, are matters constitutionally entrusted to the sound and exclusive judgment of the House, not to this court."

Stanley said it was ironic that the court was so definitive on the issue of separation of powers between the legislative and judicial branches. "To my mind, that runs contrary to what the court did in the Baker case, which was to mandate the Legislature to do the court's will," he said. The Baker case was the court's 1999 ruling that gay and lesbian couples were being unconstitutionally denied the benefits of marriage and giving the Legislature an opportunity to change the law.

The justices did not rule directly on the claims that issuing civil unions licenses or appointing an assistant to do it could be a violation of a town clerk's religious beliefs.

But it did describe the notion as "the highly questionable proposition that a public official ... can retain public office while refusing to perform a generally applicable duty of that office on religious grounds.

"We observe, however, that this proposition -- which means that the personal religious beliefs of a public officer may in some circumstances trump the public's right to have that officer's duties performed -- is neither self-evident nor supported by any of the cases cited by plaintiffs," the court said.

Nonetheless, the court said the law addressed the town clerks' concerns by expressly permitting the appointment of assistants to issue the licenses. "Thus, the law itself offers an `accommodation' for town clerks with religious reservations about issuing a civil union license," the court said.