AUGUSTA — A federal judge has ruled that Maine’s Secretary of State can’t be excluded from participating in the work of the Presidential Advisory Commission on Election Integrity, on which he serves.

U.S. District Court Judge Colleen Kollar-Kotelly’s ruling Friday in Washington, D.C., largely agrees with Matthew Dunlap’s argument that as a member of the commission he must be given access to substantive commission documents.

The opinion says Dunlap should have been granted access to documents such as a request for voter data sent to U.S. states and meeting agendas. Dunlap said in a statement that the ruling is “a clear vindication of what I have fought for.”

He sued in November, contending that the commission violated the Federal Advisory Committee Act by denying him and other members access to key documents and excluding them from much of the commission’s work.

Dunlap, one of four Democrats on the 11-member commission, says he has been kept in the dark about what the group is doing. His lawsuit alleges that the commission’s chairman, Vice President Mike Pence, and vice chairman, Kansas Secretary of State Kris Kobach, are in violation of the Federal Advisory Committee Act, which prohibits the body from excluding commissioners from deliberations and information. The Executive Office of the President is also a named defendant, as the office is staffing the commission and maintaining its records.

Dunlap has said that his goal in the lawsuit is to bring the commission into compliance with federal law. He noted in an interview with the Portland Press Herald that he had to learn from a reporter that a commission staffer had been charged with possession of child pornography. Dunlap said he hadn’t even been aware that the staffer, Ronald Williams II, had been hired.

“I was like: I need to know what’s happening, what we’re working on,” he said in the interview.

Election experts say the situation is highly unusual.