A lawyer suggested in a Brampton court today that a man who brought forward conflict-of-interest allegations against longtime Mississauga Mayor Hazel McCallion is merely "a straw man" for her opponents on council.

Mississauga resident Elias Hazineh brought the case forward alleging McCallion voted in favour of a 2007 bylaw that would have saved her son's company $11 million in development fees.

At the time, Peter McCallion was pushing for a hotel complex and convention centre in downtown Mississauga.

Hazineh claims McCallion voted at Peel Regional council to extend a deadline so her son wouldn't pay higher development fees.

"She moved a motion to extend a grace period from 60 days to 90 days, which would have allowed her son to put his application in and would have allowed him to go under the old rates," said Hazineh. "That would have saved him $11 million."

"The mayor was trying to enrich her son using her office, using her influence," Hazineh claims.

Inside court on Monday, the mayor's defence team questioned Hazineh's credibility and alleged that he is being used by councillors opposed to McCallion.

"He is a straw man," the mayor's lawyer, Freya Kristjanson, said in court.

The mayor's defence team also suggested that Hazineh failed to bring the conflict-of-interest case forward within the required period of six weeks after learning of it.

But Hazineh said their concerns only came to light on the weekend.

"They are finding straws, they are desperate, they are trying to discredit me," he said outside court.

McCallion was not in court on Monday, though she is expected to testify later this week.

Legal documents also show the mayor plans to argue she did not know her son had a stake in the company behind the project. It’s an argument a judicial inquiry already rejected in 2011.

'A lot of people will be watching this'

Municipal lawyer John Mascarin says there is a lot of interest in the case.

"A lot of people will be watching this, there’s a significant dollar amount at stake, unlike the [Toronto Mayor] Rob Ford case, which only involved $3,150.

"Hazel McCallion has been the mayor for a long time so you have to assume that Mayor McCallion knows the rules under this act."

McCallion's lawyer has said she is not in a conflict.

But if the court finds that she is, her lawyer argues it was an error of judgment or an inadvertent mistake.

With files from the CBC's Steven D'Souza and Jasmin Seputis