Montreal Mayor Denis Coderre has confirmed that the city's traffic czar was fired following a sexual harassment complaint.

The topic came up at the French-language debate between Coderre and Projet Montreal challenger Valerie Plante, when she wanted to know why the city's record on co-ordinating traffic was so poor.

Coderre hired Pierre Lacasse to much fanfare in the spring, saying the former traffic reporter would do a lot to co-ordinate projects throughout the city.

But Lacasse was quietly dismissed less than three months into the job.

At Thursday's debate Plante said Coderre has done a poor job in managing traffic and construction, noting that his hire of Lacasse didn't work out.

Coderre shot back that Plante knew Lacasse was fired following a sexual harassment complaint -- and that as mayor, he took steps to protect female employees.

"My role was just to put a stop at it because I thought it was inappropriate especially with what we are living in Quebec these days and I said at the beginning that we were very respectiful of the me too campaign and so it was an issue," said Coderre.

Aides for Plante confirmed after the debate that the mayoral candidate knew months ago that Lacasse had been fired following alleged sexual harassment.