Ontario's Progressive Conservatives plan to move a motion of non-confidence in the minority Liberal government over the cancelled gas plants in Oakville and Mississauga.
The Canadian Press has learned the Tories have already started the legal proceedings for the non-confidence motion, which they hope to introduce before the Liberals present the provincial budget.
A senior party source says the basis for the motion is "the Liberals continued attempts to mislead the public and cover up the true costs" of their political decisions to cancel the gas plants.
The auditor-general reported last week that the cost of halting the Mississauga project in mid construction just days before the 2011 election was $275-million, $85-million more than the Liberals had been claiming.
The Conservatives say they can't see how the New Democrats could not vote for the non-confidence motion given how they too have condemned the Liberals for the "expensive" political decisions to scrap the power plants.
Until now, the NDP has voted to keep the minority government in power, and has been negotiating with the Liberals on just what it wants included in the budget.
The Tories insist the non-confidence motion is not a publicity stunt, and say the Liberals can no longer be trusted to govern Ontario.
"The gas plant scandal is just the latest in a long series of examples of this sort of waste under the Liberals, following things like eHealth and Ornge," said the Tory source.
"If they're mismanaging this one file so badly, just think about what they're doing to the rest of government that we don't know about, so on that basis we're going to be bringing forward a want of confidence motion to change the government."