A day after he became the new Liberal candidate in the stronghold of Mount Royal, Anthony Housefather is being challenged over whether or not he should keep his seat as mayor of Cote-St-Luc.

Former Cote-St-Luc mayor Robert Libman is asking Housefather to step down following his selection as the Liberal candidate.

Robert Libman, who was a founder of the Equality Party, is currently competing to be selected as the Conservative candidate for that riding.

Libman says new Liberal candidate Housefather has an obligation to leave his municipal post because of the potential for conflict of interest.

“There are many issues where people compromise their political convictions because they feel they have to deal with the city on a zoning matter or on taxation,” he said. “I think the office of mayor puts you in certain situations of conflict of interest if you're also running in another level of government.”

He claims that people who have to conduct business with the city might also be afraid to demonstrate support for something other than the federal Liberal party for fear of being denied services.

"This is a question of a mayor of a municipality being in a conflict while running in a federal election. I think you cannot dissociate the two," said Libman.

Housefather is far from the first sitting mayor to run federally, and there is no law stipulating that a sitting mayor must step down.

Libman, however, said it's a matter of optics.

“I think there are situations where you cannot dissociate being the mayor and being a candidate when you are dealing with constituents,” he said.

Housefather has no intention of resigning and accuses Libman of making this an issue just to help his campaign.

“I also don't see any difference between me being the Liberal candidate or me having been running for the past nine months to become the Liberal candidate,” said Housefather. “I don't think anyone in Cote-St-Luc has seen any level of difference in the services I provided whether they supported me or didn't support me,” he said.

A federal election is scheduled to take place no later than Oct. 19, 2015.