MONTREAL—The mayor of Montreal is on the defensive after revelations that he a flipped a Villeray duplex a decade ago without the proper permits.

Mayor Michael Applebaum was a councillor in the Cote-des-Neiges-Notre-Dame-de-Grace borough during the flip in 2004. Radio-Canada reports that Applebaum did not declare the real estate transaction as part of his assets.

The mayor bought an abandoned duplex on St-Dominique St. for $80,000 and resold it four months later for $145,000.

Applebaum sad that when he signed the declaration of assets in November 2003 he did not own the property and that he sold it before he next had to declare his assets.

Between December 2003 and March 2004 Applebaum, his father and his son renovated the property—without permits.

Applebaum said this week that he did not realize he needed building permits to change a balcony floor, windows and a door. Given that Applebaum was a real estate agent and city councillor, many people are not accepting that statement at face value.

“It was not my intention in any way to try to fraud the city of Montreal or not pay any of my permits. I will rectify that situation,” said Applebaum.

But that's not all. The mayor also didn't list a property he bought with his cousin in 2008 in the Laurentians, thinking he didn't need to. However, the company they bought the property under was registered in Montreal.

Again, he says, an honest mistake.

“It's an error. I will make sure that in the future I do not make that mistake too,” said Applebaum.

The mayor's office says the rules on declaration of assets were changed in 2010 so that elected officials can declare assets at any time in the year.

“I don't accept the explanations given by Mr. Applebaum,” said Richard Bergeron, the head of second opposition Projet Montreal. “Hey come on. He knows the rules. He knows the law. He forgot the good faith to ask for a permit. Come on.”

The mayor’s office said that if Applebaum made a mistake he will fix it—and he is willing to pay for permits he did not buy. As for the property, Applebaum said his net profit on the property was $26,000 after the renovations and taxes.

Former executive committee member Alan de Souza says the mayor no longer has the moral authority to lead.

The mayor maintains he made mistakes the average person would easily make when buying or renovating a property and that he'll correct them by paying what he owes and won't step down.

But Applebaum’s opponents say he's not the average person, he's the mayor.