The Progressive Conservatives say they'll call a judicial inquiry into the cancellation of two gas plants if they form the next government.

A senior Conservative source says they want a judge to find out what happened with the gas plants and whether there was any criminal wrongdoing.

The Liberals admitted last week that they found a third batch of documents on the gas plants, after insisting that all the relevant data was made public months ago.

The opposition parties say they don't believe that all the documents have been released because there are still no files from the premier's office or the minister of energy.

They say they also believe the cancellation of the gas plants cost taxpayers a lot more than the $230 million the Liberals claim.

The opposition parties have accused the Liberals of cancelling the Oakville gas plant in 2010 and the Mississauga plant in the dying days of the 2011 election campaign to save Liberal seats.