TORONTO -- A Liberal attempt to embarrass Progressive Conservative Leader Tim Hudak by calling him to testify at public hearings into cancelled gas plants backfired Tuesday, the opposition parties said as they accused the government of trying to turn the process into a circus.

Hudak came out swinging after being sworn in at the justice committee hearings into the Liberal government's decisions to cancel gas plants in Oakville and Mississauga at a cost of at least $585 million, more than double what the government originally claimed.

"The insinuation that anyone other than the Liberal party is responsible for this fiasco is an insult to the intelligence of every Ontarian, a betrayal of the people who are now on the hook for hundreds of millions of dollars to save a handful of Liberal seats in the last election," Hudak said under oath.

"If Kathleen Wynne and the Liberal government get away with this, they'll do it again."

Hudak accused the governing Liberals of turning the hearings into "cheap theatre" by calling him to appear when he had absolutely nothing to do with the government's decisions to cancel the gas plants to save Liberal seats in the 2011 election. It's the Liberals who need to answer questions, not the opposition parties, he added.

"We've seen conflicting testimonies from the Liberals, we've seen - to put it politely - selective amnesia, and we actually saw an intent to destroy documents that can give answers to taxpayers," Hudak said outside the committee hearings.

The Liberals wanted to highlight that Hudak also promised to cancel the partially built gas plant in Mississauga, but the PC leader said he never would have put it there in the first place, and accused the government of trying to obscure the facts.

"It's sad to say this, but the only way we'll actually get answers is to have a full judicial inquiry, that the threat of jail doors slamming behind those who are not answering these questions, hopefully that will get some truth from the Liberal members," said Hudak.

The Tories say a judicial inquiry would be a step up from the public inquiry the NDP has requested because it would be headed by a judge instead of what they said would be a Liberal-friendly appointee, although every public inquiry set up by the Liberals during their 10 years in power has been headed by a judge.

The Conservatives said they plan to call a judicial inquiry immediately if they win the next election and don't want one before then because they can't trust the Liberals to create a fair, unbiased process.

Even though the Tories and NDP couldn't agree on what type of outside inquiry they want into the gas plants, both opposition parties feel the Liberals haven't been telling the justice committee the whole truth.

"It's pretty clear that information isn't as forthcoming as people had thought it would be, particularly from the former premier and current premier," said NDP Leader Andrea Horwath. "There's still a lack of openness about who knew what when."

Horwath said she couldn't see what light Hudak could possibly have shed on the gas plants scandal unless he was a secret adviser to the Liberals in the last election, and accused the government of playing games at the committee hearings at the legislature.

"We always said from day one that this was going to dissolve into chaos around here, a bit of a circus, and that's why we wanted a public inquiry where it was taken out of this place and done professionally in an unbiased, third-party way," said Horwath.

"Instead, it's being done here, and we pretty much got the circus we expected."

Government house leader John Milloy lashed out at Hudak for refusing to answer questions about how much the Tories thought it would cost when they promised to cancel the Mississauga gas plant.

"Mr. Speaker, 28 times direct questions were put to the Leader of the Opposition ... and 28 times he would not answer a single question," said Milloy.

"I have not seen skating like that since I saw those old clips of Barbara Ann Scott on TV."

Former premier Dalton McGuinty told the committee last week he had no idea what it would cost when he made the political decisions to cancel the two gas plants, but insisted it was the right thing to do in the face of widespread local opposition.