The Province of Manitoba says it could be out up to $500 million because Statistics Canada underestimated the number of people in the province.

Manitoba’s finance minister, Jennifer Howard, was in Meech Lake, Que. on Monday as part of a two-day meeting of the country’s finance ministers.

While the Canada Pension Plan was the hot topic for many ministers, Howard was pushing for federal Finance Minister Jim Flaherty to clear up a census error that has cost the province millions.

Howard said the 2011 census undercounted Manitoba’s population by as many as 18,000 people. The census was carried out during one of the biggest floods in the province’s history, while many residents were displaced.

Howard said the province has also seen the number of income tax returns growing at a much faster rate than what was estimated by Statistics Canada.

“Those people exist. We have to provide health care and education to them though we aren’t getting recognized for them,” said Howard.

She said federal transfer payments that cover things like health care and education will be $37 million less than what they should be this fiscal year and as high as $100 million next year. If the error is not corrected, Howard said, it could cost Manitoba $500 million over the next five years.

“We have been working with Statistics Canada on this. We will continue to do that,” said Howard. “We are going to make a proposal to them then we work together to fund and redo the study.”

Howard added the province was willing to foot the bill to review Statistics Canada’s 2011 census findings for Manitoba.

But officials from Statistics Canada officials said its numbers have already been double-checked in a review study, and it has no plans to do a second review.

Jane Badets, a director with Statistics Canada, told CBC Manitoba response rates for the 2011 census were actually quite high, and while the agency does miss some people studies are posted to adjust for those missed.

Badets added the agency uses methodology agreed to by multiple provinces.