TORONTO -- The Progressive Conservatives' non-confidence motion in Ontario's minority government over the cancellation of gas plants is just a headline-seeking gimmick, both the Liberals and New Democrats said Monday.

"I saw the line that it's not a publicity stunt, but I think when people say that it usually is a publicity stunt," said Liberal house leader John Milloy.

The New Democrats, who have been as critical as the Conservatives of the decisions to cancel gas plants in Oakville and Mississauga to save Liberal seats, refused to say if they'd support the Tory non-confidence motion.

The Tories need unanimous consent to bring the motion to the floor for debate, and the Liberals will never agree to that, predicted NDP Leader Andrea Horwath.

"I think it's more about grabbing headlines and getting attention than it is about a serious motion," said Horwath.

"The last thing people want in this province is political games that are going nowhere just for the sake of headlines."

However, the Conservatives said they are very serious about the 'want of confidence' motion, which they hope to introduce before the May 2 budget.

"This is a very strong indication that the PC party is not willing to support this government, and we're asking the NDP to stop propping up a corrupt government," said Conservative house leader Jim Wilson.

Horwath should reconsider her position on the non-confidence motion, added Wilson.

"I would hope she would rethink that after she gets a chance to read it," he said.

"To be fair I don't want to crap on the NDP at this point because the fact of the matter is we haven't shared the wording (of the motion) because we're still working with the lawyers on it, but this is a legitimate tool and I would hope the NDP would embrace it as such."

The Tories have been meeting with the Clerk of the Assembly and legislative counsel to draft the motion against the minority Liberal government for "not being truthful" about the costs of cancelling the gas plants.

An auditor general's report last week found the true cost of halting the Mississauga plant in mid-construction, just days before the 2011 election, was $275 million, not the $190 million Premier Kathleen Wynne and the Liberals have been claiming.

In the legislature, Tory Todd Smith noted Wynne was acting as chair of cabinet when the Liberals decided to scrap the Oakville plant, and demanded she say how much the project actually cost without waiting for her promised appearance before the justice committee hearings into the cancelled energy projects.

"Premier, surely we shouldn't have to haul you before committee like some Quebec construction industry snitch just to get an answer to a question," said Smith.

"How long do you really expect the Liberal farm team to my left (meaning the New Democrats) to prop you up and prop up your scandal-plagued government when you can't even answer a simple question?"

Wynne punted the question to Energy Minister Bob Chiarelli, who said the government wanted to wait for the auditor's report on Oakville because it was a very complicated contract with many complex variables to be considered in determining the final cost.

"We are awaiting the report of the auditor general to deal with those difficult clauses in trying to calculate the cost," said Chiarelli.

The energy minister also took a shot at PC energy critic Vic Fedeli, known for his trademark yellow neckties and for his aggressive questioning of witnesses at the gas plant hearings.

"I think he wants to change his yellow tie in for a trench coat and call himself Columbo, because he's trying to parse and split every fact and every answer in committee and make a tremendous scandal out of it," charged Chiarelli.