A federal appeals court on Tuesday upheld Maine’s campaign disclosure law that requires the anti-gay National Organization for Marriage to release its donor list, but the group vowed to take the fight to the U.S. Supreme Court to prevent revealing who financed a $1.8 million movement that helped overturn the state’s gay marriage law.

The panel on the U.S. Court of Appeals for the First Circuit in Boston rejected the NOM’s argument that being forced to disclose donors who backed the effort was a violation of First Amendment speech rights.

The court’s decision on Tuesday means the National Organization for Marriage, which advocates that marriage be defined as being between a man and a woman, could have to reveal the names of people who gave more than $100 to its campaign efforts against same-sex marriage in Maine. The Maine law says that groups that spend more than $5,000 “for the purpose of initiating or influencing” a referendum must disclose the names of their donors. The decision by a panel on the U.S. Court of Appeals for the First Circuit in Boston clears the way for the state to conduct an inquiry into whether the group was indeed raising money to influence the ballot initiative. via: Reuters

The group’s lawyer, James Bopp Jr., said it was unfair that advocacy organizations should face the same disclosure requirements as political action committees.

“The homosexual lobby has launched a nationwide campaign to harass supporters of traditional marriage,” said NOM’s lawyer, James Bopp Jr.

Bopp called it “unfair” that advocacy organizations should face the same disclosure requirements as political action committees.

The bill to allow same-sex marriages in Maine was signed into law on May 6, 2009, by then-Gov. John Baldacci following approval by state lawmakers, but was overturned in a ballot referendum on November 3, 2009 after anti-gay opposition groups led by the NOM won that vote by 52.8 percent.

Two recent polls indicate that 53 percent of Mainers now favor same-sex marriage, and the measure appears to be headed back to the ballot for a second time.

Last week, marriage equality advocates submitted petitions signed by 105,000 voters, far more than the 57,277 needed to force a referendum in November.

If same-sex marriage passes at the polls, Maine could become the first state to approve gay marriage through a popular vote.