AUGUSTA, Maine — The Maine Supreme Judicial Court ruled Tuesday that the National Organization for Marriage must disclose its donor list in connection with the group’s support of a people’s veto of Maine’s 2009 same-sex marriage law.

The National Organization for Marriage has already paid a record-breaking fine of $50,250 to the Maine Ethics Commission and registered as a ballot question committee, but it continues to resist revealing its national donor list. The organization had requested a stay on the release of that list while its case against the ethics commission is pending in the Law Court, but Tuesday’s decision essentially denies that request.

Joseph A. Vanderhulst, one of the attorneys representing the National Organization for Marriage in the Maine case, said the organization is in talks with the Maine Ethics Commission and the state attorney general’s office about the release of the donor list.

“This is unprecedented,” said Vanderhulst. “The commission is stretching the definitions that are in Maine law and are also applying the law to [the National Organization for Marriage] in a way that they have not applied it to other organizations that have done the same thing. … To date, this is the first time that any jurisdiction has required this of [the National Organization for Marriage].”

The Law Court justices wrote that the National Organization for Marriage’s arguments in the larger case are not strong enough that there is a likelihood that the commission’s decision to demand the donor list would withstand future legal challenges.

“The circumstances underlying the commission’s decision occurred almost six years ago and the decision has successfully withstood federal and state court challenges during that time,” reads the decision. “[The National Organization for Marriage] now asks us to decide many of the same issues and has failed to sufficiently show that it has a likelihood of succeeding on the merits. Accordingly, we deny [the National Organization for Marriage’s] motion for a stay pending appeal.”

The conflict between the National Organization for Marriage and the ethics commission dates back to October 2009 when the commission launched an investigation of the group’s role in the campaign after a complaint from a California activist who argued that the National Organization for Marriage should have been required to register as a ballot question committee. Any group that spends more than $5,000 to influence a referendum in Maine is required to register as a ballot question committee and as such, must reveal the identities of its donors.

The National Organization for Marriage funnelled more than $2 million to a political action committee called Stand for Marriage Maine, which represented 64 percent of the PAC’s spending in the referendum, which resulted in the repeal of the same-sex marriage law enacted by the Legislature and Democratic Gov. John Baldacci. Same-sex marriage was reinstated in Maine in another referendum in 2012.

The National Organization for Marriage has argued that the Maine Ethics Commission misapplied the law in ruling that its donors from across the United States were supporting the organization’s general principles and not specifically the referendum in Maine. The organization also has argued that disclosing its donors would seriously hinder its ability to raise funds in the future.

In May 2014, Maine Ethics Commission Chairman Walter McKee said that the National Organization for Marriage has made a “mockery” of Maine’s campaign finance disclosure laws.

The organization has already paid the $50,250 fine and registered as a ballot question committee “under protest,” according to Maine Ethics Commission Executive Director Jonathan Wayne, but has so far not revealed its donors. Wayne said that list would be published on the commission’s website when it is received.

Vanderhulst said there are no other legal avenues to appeal the issue of the stay.

“The Maine Law Court is the highest court and them saying no on the stay means [the National Organization for Marriage] has to disclose its donor list,” he said, adding that he was disappointed to see the decision released on Tuesday, which also was the deadline for the organization’s written arguments in the larger case.

The court has briefings scheduled for October and will determine then whether to proceed with the case.

Attorney General Janet Mills said in a written statement Tuesday that she is relieved that the issue is finally resolved.

“[The National Organization for Marriage] has fought for almost six years to skirt the law and to shield the names of the out-of-state donors who bankrolled their election efforts,” said Mills. “The time has come for them to finally comply with state law like everyone else. The people of Maine have a right to know who is paying to influence our elections.”

Christopher Cousins has worked as a journalist in Maine for more than 15 years and covered state government for numerous media organizations before joining the Bangor Daily News in 2009.