TORONTO - The Progressive Conservatives are demanding a judicial inquiry into cancelled gas plants in Oakville and Mississauga, saying only the threat of jail will get some people to tell the truth.

PC Leader Tim Hudak came out swinging today as he began his testimony at the justice committee hearings into the Liberals' decisions to scrap the gas plants, at a cost of at least $585 million.

Hudak said only the Liberals are to blame for the expensive decisions to save Liberal seats in the 2011 election, and warned "if they get away with it this time, they'll do it again."

He said the only way to get real answers for taxpayers is a judicial inquiry that could jail people who don't tell the truth.

The Liberals called Hudak before the committee to try and embarrass him for also promising to cancel the partially built Mississauga gas plant, but the PC leader said he never would have built it there in the first place.

Hudak accused the government of trying to turn the committee hearings into a circus with his appearance, calling it "cheap theatre" and an attempt to obscure the real issues.