The Massachusetts state Senate voted Wednesday to ask the state's highest court whether a bill authorizing civil unions would meet the court's recent ruling that Massachusetts cannot prohibit gay marriages.

State lawmakers here have been grappling with how to deal with the politically sensitive issue since the Supreme Judicial Court ruled Nov. 18 that any prohibition in Massachusetts law on gay marriage is unconstitutional. The court gave the legislature 180 days to bring state statutes into compliance. Unlike most state courts, in Massachusetts the Supreme Judicial Court is required to provide legal advice to lawmakers when they request it on specific proposed legislation rather than waiting to rule on legislation in the context of lawsuits.

"We thought all along that we needed a clarification," said Ann Dufresne, the communications director for Senate President Robert E. Travaglini (D). A longtime proponent of civil unions, he opposes same-sex marriage rights and led the effort to ask the court for advice.

"It was a significant ruling, and there have been many, varied legal opinions as to exactly what it means. Now we will wait for the court to respond," Dufresne said.

Immediately after the court's 5 to 4 decision, many state political leaders, including Gov. Mitt Romney (R) and Attorney General Thomas F. Reilly (D), argued that the ruling left open the possibility of either a constitutional amendment banning same-sex marriage or finding some middle ground, perhaps through a civil unions bill like the one passed in Vermont in 1999, which confers many of the legal and financial benefits of marriage.

House Speaker Thomas M. Finneran (D), who also opposes gay marriage, told a group of local newspaper editors and reporters last week that legislators also have the option of doing nothing and letting the court's ruling stand. He added that he had not yet decided which course of action he preferred.

Meanwhile, proponents of same-sex marriage have portrayed the court's ruling as a clear-cut statement that anything short of full marriage rights for gay couples is unconstitutional. The benefits of civil unions, they say, would not extend beyond the borders of the state.

"I think for many of us the court's decision is still crystal clear. The problem is it is not crystal clear to everyone," said State Sen. Cheryl Jacques (D).

Jacques, who is gay and is leaving the Senate on Jan. 4 to head the Washington-based Human Rights Campaign, a gay rights advocacy organization, added: "I don't have a problem with the Senate asking the court to say it again for those in the room who didn't get it the first time. A civil unions bill is ill-advised. It will be deemed unconstitutional. If it takes the court saying that again for everyone to get it, then that is still forward progress."

Senate leaders said it is unclear when the court will reply to their request. The court took several months longer than expected to make its initial ruling on gay marriage last month.

Wednesday's initiative came in an informal session while the legislature is officially in recess for the holidays.

With no objections raised during a voice vote, the Senate pushed the civil unions bill to a third reading, one step before passage, and then approved an order seeking an advisory opinion on the bill from the Supreme Judicial Court.

The legislature will reconvene in early January, and a constitutional convention is scheduled for Feb. 11, at which time lawmakers are scheduled to vote on an amendment that would define marriage as between a man and a woman and would also ban civil unions.

Finneran has said the amendment would be unlikely to pass unless the language outlawing civil unions is dropped.

To be placed on the ballot, under Massachusetts law, a constitutional amendment must pass in two consecutive legislative sessions, meaning that the earliest voters could consider it would be November 2006. Romney has said he favors the amendment. A series of public opinion polls since the court decision have shown that a majority of state residents favor legalizing gay unions.

A previous attempt to initiate a amendment that would bar same-sex marriage was derailed in July 2002, when then-Senate president Thomas F. Birmingham (D) led an effort to adjourn the constitutional convention without a vote.

Ron Crews, president of the Massachusetts Family Institute, a conservative group that is leading political opposition to same-sex marriage in the state, said he is hoping that the court tells legislators that the bill does not conform with its ruling.

"We are against same-sex marriage and also against civil unions, so we hope they say, 'Sorry, this won't work,' " Crews said. "We will push for the constitutional amendment that will usurp the court's action, and we are also looking into other legislative means of doing so."

Crews said that his organization has been meeting with legal experts to determine what means are available to undo the state court's decision, and that a course of action could be announced as soon as next week.