TORONTO -- The $585-million price tag for the cancellation of two energy projects in Ontario is expected to rise even higher Tuesday when the province's new auditor general releases a special report.

A previous auditor's report on the Liberal government's decision to kill a partially built gas plant in Mississauga in the middle of the 2011 election campaign put the cost of that project at $275 million, $85 million higher than the Liberals had been claiming.

Newly appointed auditor general Bonnie Lysyk's report will detail the cost of cancelling a gas plant in Oakville and moving it to Kingston area -- which the Liberals put at $40 million, but the Ontario Power Authority estimated at $310 million.

The auditor signalled the same criteria from the Mississauga plant report would be used in examining the cost of cancelling the Oakville plant, which means lowering projected savings the government had been claiming for the 20-year contract with the plant's developers.

"They (Liberals) have at every single instance tried to prevent us from getting the true costs," Progressive Conservative energy critic Lisa MacLeod complained Monday.

"This strikes at the very heart of our democracy, if a government can spend hundreds of millions of dollars to save seats in an election."

The opposition parties called the decisions to scrap the plants "an expensive Liberal seat saver program" for the 2011 election, when the governing party fell one seat short of a majority, but held on to all five seats around the cancelled energy projects.

"What's really clear is that this government did the wrong thing when it came to using the gas plant debacle as a way to try to save their own seats," said NDP Leader Andrea Horwath.

"They moved these plants and didn't care what the cost would be to taxpayers or rate payers, and they did it for political reasons, and I think that's the thing that's most disturbing to folks.

Premier Kathleen Wynne said Monday she asked the auditor to probe the cost of cancelling the Oakville plant so people could get the answers they were looking for.

"There were things that happened in terms of relocation of the gas plants that shouldn't have happened. I've apologized for that," said Wynne. "I'm not defending those decisions. In fact, I've said that there were decisions that were made that shouldn't have been made."

Former premier Dalton McGuinty has said he made the decisions to scrap the gas plants, insisting the government was slow to understand that local residents were correct in not wanting the generating stations so close to homes and schools. Unlike Wynne, McGuinty has refused to apologize for cancelling the two projects.

However, the Tories pointed out that Wynne was one of the cabinet ministers who signed off on the cancellations, and was Liberal campaign co-chair at the time the decisions were made.

"We have asked Kathleen Wynne consistently what the true costs was ... only to have been obstructed by her house leader," said MacLeod. "The information and privacy commissioner was obstructed by that government."

Privacy commissioner Ann Cavoukian reported in June that top Liberal staff in McGuinty's office broke the law by deleting all emails related to the cancellation of the two gas plants. A month later, Cavoukian was "dismayed" to learn a number of gas plant emails she was told could not be found were recovered by the government.

The Liberals' initial refusal to release emails and other correspondence related to the gas plants led to a preliminary finding of contempt of Parliament against the government, and a bitter debate that prompted McGuinty to prorogue the legislature last October and resign as premier.

Horwath warned that Wynne and the Liberals would have to take responsibility for the final price of cancelling the gas plants, but the premier said she wasn't worried about political fallout.

"It's not about my political future or our political future; it's about getting information for the people of Ontario so there's an understanding of what the cost was in changing the venue of those gas plants," she said. "I think that this will give us more clarity on the costs and that's why I asked for the report."