The union that represents Midlothian’s public works employees says it plans to strike and said the village has engaged in an unfair labor practice.

Local 150 of the International Union of Operating Engineers announced the strike plans in a news release Wednesday, and said it had lodged an unfair labor complaint with the Illinois Labor Relations Board.

The village is working with a mediator to come to terms on a contract covering the 12 employees and said in a statement Thursday it was surprised by the union’s notice of intent to strike.

A specific strike date was not identified, but Local 150 said the strike is set to commence after a mandatory five-day notice period.

In its filing Wednesday with the state labor board, the union cited an exchange of text messages Feb. 9 between the village’s bargaining consultant and a member of the bargaining unit.

The union alleges the texts by the village consultant was an “attempt to mock the union’s attempts to improve the terms and conditions of employment” for union members. The complaint alleges the messages amounted to coercement of bargaining unit members.

“The Village Board and bargaining team are disappointed that the union chose to negotiate in the media rather than at the bargaining table,” the village said in its statement. “The Village and Local 150 have a long history of amicable and professional negotiations that have led to mutually satisfactory bargaining agreements.”

“It is hoped the union will return to the bargaining table and join the Village in good faith discussions to secure a fair bargaining agreement between the parties,” according to the statement.

The village warned that the union would be violating terms of the current contract, and that employees could be fired or otherwise disciplined if they walk out.

The village’s bargaining agreement with the union includes a no-strike clause barring the employees from a work stoppage.

Local 150 said its members are striking not only to address the alleged unfair labor practice, but also to advocate for a fair and equitable contract. Key demands include wages and insurance, the union said.

The union is seeking insurance coverage for bargaining unit retirees, something it says is available to other village employees.