Mississauga homeowners could see their property taxes increase as a result of a recently passed provincial housing bill, Mayor Bonnie Crombie warned on Wednesday.

At a news conference, Crombie said Bill 23, or the More Homes Built Faster Act, "will be a big hit to your wallet," noting that the average property tax could go up by five or 10 per cent or approximately $300 to $600.

The legislation reduces and exempts fees developers pay to construct affordable housing, non-profit housing and inclusionary zoning units. While waiving fees could encourage more housing to be built, Crombie argued that nothing in the legislation guarantees that they would not be passed onto homeowners.

"Under Bill 23, property taxpayers will be funding developer profits. While we can agree and certainly appreciate the province's desire to incentivize affordability, it can't be done on the backs of cities and our taxpayers," Crombie said.

"None of this is fair to our property taxpayers or our residents."

She indicated that property taxes could further increase as the Region of Peel is likely to implement a hike that is "equal or greater to the one we're facing here at the city," which means one household may see an average total hike of between $600 and $1,200.

Crombie said the City of Mississauga could lose up to $885 million over 10 years in development charges due to the housing law.

"That is equal to losing 20 per cent of our capital budget. The numbers are devastating. And they're baffling and deeply concerning," Crombie said.

Municipalities have sounded the alarm about the implications of Bill 23 on their finances. The Association of Municipalities of Ontario said the legislation could leave their members short $5 billion. On Wednesday, Toronto Mayor John Tory warned that if the Ontario government does not come up with a plan to help municipalities to cover the shortfall caused by the legislation, "we will ramp up our campaign against this legislation."

Meanwhile, Steve Clark, Ontario's municipal affairs and housing minister, wrote a letter to Tory saying that "the City of Toronto is made whole when it comes to the impact" of Bill 23. He also announced Wednesday that the province would launch a third-party audit of city finances to determine if Toronto will suffer a revenue shortfall due to the housing law.

While Clark has not indicated if other municipalities will undergo the same audit, Crombie said she would welcome the province to do so. She noted that it is not true that municipalities are sitting on large amounts of reserves.

"I would welcome the opportunity to correct the record and run the province through our numbers. We are fiscally responsible in Mississauga. I would also welcome a similar commitment that Mississauga be compensated for any losses from Bill 23," Crombie said.

"We want to work with the province to achieve our shared goal of addressing affordability and building more homes. We just need to get on the same page as to how we get there."

On top of the impacts of Bill 23, Crombie said Mississauga is also facing a $52 million deficit in 2023 due to the COVID-19 pandemic.

"It will be a very challenging year, one in which we'll have to look at reducing services or programming or delaying our capital expenditures, delaying our capital budget and our capital plans," she said.

- with files from The Canadian Press and CP24's Joshua Freeman