A local union representing dozens of behind-the-scenes workers at WBZ has shut down a face-to face debate between Mayor Martin J. Walsh and City Councilor Tito Jackson.

The International Brotherhood of Electrical Workers, Local 1228, sent a letter to both men this week urging them to boycott Tuesday’s proposed debate until the station and its parent company, CBS Boston, agree to higher wages for longtime employees.

Both men agreed to support the union’s wishes.