TORONTO - The Progressive Conservatives didn't even wait for Tuesday's throne speech opening the new session of the Ontario legislature before reviving the contempt of parliament charge against the Liberals over cancelled gas plants in Oakville and Mississauga.

The Tories announced they would write Speaker Dave Levac asking him to consider the contempt motion before the throne speech, although debate on the motion itself would not come before Wednesday.

"It’s becoming increasingly clear that MPPs have been obstructed from obtaining the truth about the gas plant cancellations," said Conservative Todd Smith.

"I intend to raise this issue with the Speaker to find out who ordered the coverup, and what else the McGuinty-Wynne Liberals are hiding."

The contempt motion names former energy minister Chris Bentley, who resigned his seat last week, but the Tories say it's really about finding out who made the decisions to cancel the two gas plants and who ordered the coverup of relevant documents.

"This is more than a contempt motion against one individual," said Smith. "It’s about protecting taxpayers and holding an increasingly shady government to account."

Premier Kathleen Wynne has said she wasn't involved in any meetings or decisions to cancel the two energy projects, which cost Ontario taxpayers at least $230 million.

The Opposition estimates the true cost of the cancellations could top $1 billion, and point out Wynne was the Liberal campaign co-chair in 2011 when the party halted the Mississauga gas plant in mid-construction just days before the Oct. 6 election.

"We wasted potentially $1.3 billion of taxpayers’ money so that these guys could buy an election in 2011," said Smith. "We can’t allow that to happen."

Legislative business virtually ground to a halt last fall as members debated the Tories' original contempt motion, which triggered then-premier Dalton McGuinty's decision to prorogue the legislature for four months, until the Liberals picked his successor.

The New Democrats said they too have a lot of questions about the gas plants, but would prefer to see one committee set up to study both the cancellations and the Liberals' initial refusal to release all relevant documents.

"We need to be able to deal with who made the decisions about the cancellations and why and how much it would cost ... and No. 2, who refused to release those documents," said NDP house leader Gilles Bisson.

"If we can do that and wrap it up into one committee, I think we can get to where we’ve got to go."

Wynne has agreed to restrike all the committees that were dissolved last fall, including one to study the gas plants, but the Conservatives said the Liberals attached conditions that they can't accept.

"They wanted us to set aside the issue of contempt in exchange for the select committee, and we’re not going to do that," said PC house leader Jim Wilson.

"This issue is a separate issue and is far too important. Governments simply cannot be allowed to ignore orders of the house or committees."

Government house leader John Milloy said he was "disappointed" in the Tory tactic to refile the contempt motion, which he warned could tie up legislative business again as it did last fall.

The Tories also released a television ad Tuesday claiming newly released documents show Wynne was briefed on Project Vapour, the Liberals' code name for the cancelled gas plants, and asking if the new premier "choose to forget" her role in the scandal.