AUBURN — Saying the Auburn School Committee is violating labor laws, the union representing Auburn teachers, education technicians and other support workers have filed a complaint with the Maine Labor Relations Board.

Both sides are at an impasse, and teachers and other staffers have worked without contracts since June, union representative Carl Bucciantini said.

Superintendent Katy Grondin disagreed with Bucciantini’s complaint. She is filing for a fact-finding with the labor board.

 Negotiations on a three-year contract for 2015-18 began more than a year ago.

“We reached a point where discussions weren’t fruitful. We decided to go to mediation,” Bucciantini said. “This is one of the points of disagreement: When a contract goes into mediation, both sides list the topics to be discussed. Only those topics are on the table.”

The mediation sessions were held four of five times last summer. Eventually, both sides agreed on salary, insurance and other language, Bucciantini said.

“There was give and take,” he said. “Both sides felt comfortable or we wouldn’t have agreed.”

After signing the agreement, the administration said, “’Now we want to talk about a few other remaining things,’ which is what broke the camel’s back,” Bucciantini said.

Those issues had to do with seniority and reduction in force, and retirement, he said. “We’re not opposed to that necessarily, but we are opposed to the process. Our point it’s bad-faith bargaining.”

Lawyers for the union and administration talked but were unable to reach a middle ground, he said.

He said union leaders should have been able to take the agreement, written by the mediator and signed by both sides, to take to the union members for a contract vote.

What happens next is up to the Maine Labor Relations Board.

Auburn has more than 300 teachers. Bucciantini works as a K-12 technology integrator for the Auburn School Department. He started working for the Auburn School Department in 1984.