BOSTON (AP) – Opponents of same-sex marriage are withdrawing a federal lawsuit that sought $5 million from lawmakers who voted in November to recess a joint session of the legislature in an effort to kill a proposed constitutional amendment outlawing same-sex marriage.

The lawsuit, filed last month in U.S. District Court by Voteonmarriage.org, argued the 109 lawmakers who voted to recess a joint constitutional convention violated the supporters’ rights to free speech, to petition the government and due process under the law.

The lawsuit sought $500,000 from the lawmakers for the cost of the group’s legal battles and another $5 million in punitive damages.

On Jan. 4, two days after the legislature voted to advance the proposed amendment to the new legislature, the group withdrew the suit.

Glen Lavy, an attorney with the Arizona-based Alliance Defense Fund which represented Voteonmarriage.org in the lawsuit, said there wasn’t any reason to pursue the suit, which also asked the court to regard the 109 votes to recess as votes in favor of the amendment.

“Now that the legislature has chosen to do the right thing and vote, there is no need for this lawsuit to continue,” he said.

The decision to withdraw also follows the threat of a countersuit by 14 of 109 lawmakers. The lawmakers sent a letter to Voteonmarriage.org on Dec. 29 calling the suit frivolous and giving them 21 days to withdraw it.

The lawmakers faulted the lawsuit saying it tried to pursue them both as officials and as private citizens. It also argued that legislators are immune from liability for actions taken as lawmakers.

On Jan. 2, lawmakers voted 62-134 to forward the amendment on to the new legislature, which was sworn in on Jan. 3. Just 50 votes are needed when the question comes up again during the new two-year session to put the amendment to voters on the 2008 ballot.

Some lawmakers cited a ruling by the Supreme Judicial Court that they had a constitutional duty to take an up or down vote on the proposed amendment as a reason not to try to kill the amendment by parliamentary tactics.

They were also given little chance. Senate President Robert Travaglini, who presides over the joint session, known as a constitutional convention, quickly called a roll call vote on the amendment. Travaglini, who supports civil unions but opposes same-sex marriage, voted in favor of placing the proposed amendment on the ballot.

Travaglini hasn’t said when he would call a new constitutional convention, but said he would only set a date in consultation with House Speaker Salvatore DiMasi, D-Boston, who supports same-sex marriage.

DiMasi and other same-sex marriage supporters are hoping to change enough votes to defeat the proposed amendment before it reaches the ballot.