BOSTON (AP) – A constitutional amendment that would eliminate the nation’s first legally sanctioned gay marriages but legalize civil unions survived three votes Thursday and stood one vote away from victory for this legislative session.

The Legislature recessed just before midnight Thursday and planned to return March 29 to resume deliberations. If it survives a final vote and legislative maneuvering by opponents, the measure would then be put on hold until the 2005-06 session, when a newly elected Legislature will be required to approve an identical measure before sending it to the voters in November 2006.

Even if the amendment does pass, it would not stop the gay marriages that are scheduled to begin May 17 under a landmark high court decision that ruled it was unconstitutional to bar gay couples from marriage.

Months of negotiations and apparent impasse on a constitutional amendment ended Thursday, when a constitutional ban won its first round of approval – a month after three separate versions met narrow defeats. It then passed two other votes without much resistance.

The third vote appeared to be a defeat for gay-rights advocates who had been strategizing through the night, supporting the amendment on the first two votes and then withdrawing their support on the third one.

House Republicans, who had opposed the amendment on the first two rounds, switched their votes as well, negating any potential impact on the final vote.

Opponents of gay marriage had spoken out passionately against this version of an amendment, arguing that the merger of a ban on gay marriage and approval of civil unions would ask voters to render a single verdict on two diametrically opposed policies.

“The language of that vote is confusing at best to the electorate and will probably, if put on the ballot in that fashion, be defeated,” said Rep. Philip Travis, D-Rehoboth, the sponsor of the original amendment, which would have banned gay marriage and made no provision for civil unions.

The vote in favor of the ban occurred against a backdrop of renewed protests on Beacon Hill, where the Legislature resumed its constitutional convention after a monthlong hiatus filled with behind-the-scenes negotiations.

Ron Crews, head of the Massachusetts Family Institute, which has led the opposition of gay marriage, acknowledged the outcome remained unclear, but was encouraged.

“The silver lining out of this is you saw a desire here to protect marriage,” he said.

The first constitutional convention in February ended in a deadlock after two days of passionate debate, pitting civil rights for gay couples against the desire to preserve the traditional definition of marriage.

While the national landscape has shifted dramatically since lawmakers last convened, with unsanctioned gay marriages occurring across the country and President Bush endorsing a federal amendment, the spotlight remained on Massachusetts because of its unique status as the only state where the marriages are legal.

“No Hatred. Just loving biblical truth,” read posters held by some of the opponents of gay marriage who gathered on the Statehouse steps.

Lynn Tibbets, 50, of Boston, held a sign urging “No discrimination in the constitution.”

“It used to just make me mad – the people on the other side. Now it just makes me sad,” Tibbets, a financial management consultant, said as she choked back tears.

If an amendment wins final approval, House Speaker Thomas Finneran has said he will seek to prevent the issuance of marriage licenses – and the potential legal confusion it could cause – until the voters are able to weigh in on the amendment.

Gov. Mitt Romney, who opposes gay marriage, has said he would also seek to avoid the legal confusion, but has committed to following the law as it exists May 17.

porters resumed their post outside the House chambers, singing patriotic hymns and protest ballads, as they did for hours on the last day of the February debate, forcing lawmakers to walk through their ranks as they went to take successive votes on the amendment.

Many opponents of gay marriage came to the Statehouse wearing baseball hats with crosses on them and shirts bearing biblical phrases, promoting heterosexual marriage. Interspersed among the singers, they prayed silently and sang competing hymns.

“Unfortunately, they believe we don’t like them,” said Maria Reyes, 51, of Boston, an elementary school teacher who came to support a same-sex marriage ban with the Hispanic Baptist Church in Boston. “That’s not the issue here. We need to obey God’s will.”

AP-ES-03-11-04 1804EST