BOSTON (AP) – A proposed constitutional amendment to halt same-sex marriage is a step closer to making the 2008 Massachusetts ballot, but the governor-elect said that the fight to preserve the state’s unique same-sex marriage rights will continue.

Lawmakers voted on Jan. 2 to advance the proposed amendment, which would define marriage as the union between a man and woman.

The measure still needs approval in the next legislative session before it can appear on the ballot, and both supporters and opponents of same-sex marriage promised to step up their campaigns.

“This fight isn’t over,” said Democratic Gov.-elect Deval Patrick, who opposes the amendment.

Patrick had been out of the country until Jan. 1, and he had conducted a furious round of last-minute lobbying to try to prevent the vote. If the Legislature had recessed on Jan. 2, the final day of its session, without voting, amendment supporters who had collected more than 120,000 signatures would have essentially had to start over.

“This is democracy in action. It’s not a vengeance campaign. It’s not a hate campaign. It’s just an opportunity for the people to vote,” said Kris Mineau of the Massachusetts Family Institute, which backs the amendment.

Gov. Mitt Romney, an opponent of same-sex marriage and possible candidate for the GOP 2008 presidential nomination, called the vote to advance the proposed amendment an important step on the path to the ballot box.

“This is a huge victory for the people of Massachusetts,” he said.

About 8,000 same-sex couples have wed in Massachusetts since the Supreme Judicial Court ruled in 2003 that the state Constitution guarantees gays and lesbians the right to marry. A few other states offer civil unions with similar rights for same-sex couples, but only Massachusetts allows same-sex marriage.

“There are thousands and thousands of supporters who are committed to ensuring that the rights of a few are never put to a public popularity ballot,” said Marc Solomon, campaign director for MassEquality, a gay rights group.

House Speaker Salvatore DiMasi, who had avoided calling the proposed amendment to a vote last fall, said its wording discriminates against gays and lesbians.

One state lawmaker, Rep. Philip Travis, said the legislature was simply upholding its duty to respond to a petition calling for a statewide vote on the issue.

The state’s high court had admonished the legislature for avoiding a vote on the citizen petition last fall but said it had no power to intervene.

The amendment needs to be approved by 50 members of the current legislature and 50 members of the new legislature before going to voters on the 2008 ballot. The Jan. 2 vote fulfills the first part of that process.

Supporters of same-sex marriage say the tide is in their favor.

Seventeen lawmakers who voted won’t be returning in the new legislative session, including some of the most vocal opponents of same-sex marriage. Same-sex marriage supporters say they will pick up a total of seven votes to block the proposed amendment in the new session, according to Solomon.