Ontario Premier Kathleen Wynne promised to tell “the truth that I know” when she testifies about the province’s cancelled gas plants at a legislative committee on Tuesday afternoon.

“I will answer all the questions,” she said on Tuesday morning. “I will tell the truth at every juncture, as I understand it, at every juncture.”

She added, “I always tell the truth, Mr. Speaker. The truth that I know. Absolutely.”

Wynne was grilled during question period by opposition MPPs who had fresh fodder for their criticism of the government’s cancellation of the Oakville plant just ahead of the last election: earlier on Tuesday, the CEO of the Ontario Power Authority told a legislative committee that the Liberal government has known for months that the net cost of cancelling the Oakville plant was potentially $310 million. That is almost eight times higher than the $40 million figure the government has been citing.

At times the opposition members were banging their desks so loudly, government members had to sit down in the middle of their responses.

“I’m trying to get control,” Speaker Dave Levac said. “I’m seeking your co-operation.”

Wynne’s response to the new figure was that the OPA has reported different numbers at different times. But she agreed she is “not happy” about the situation, and that there needs to be a better process going forward.

“I regret that this situation evolved the way it did,” she said, adding that in the future, the community should be involved earlier on.

Wynne did not respond to questions from the PCs and the NDP about when exactly she was briefed that the $40 million figure was inaccurate, but indicated she would answer any questions put to her at the committee meeting.

The PCs used the new information from Ontario Power Authority CEO Colin Andersen to push for the Liberals to agree to their non-confidence motion. But Wynne repeated her position that the budget, to be tabled on Thursday, is the appropriate time for members to express their confidence or non-confidence.

She also repeatedly reminded the PCs and NDP that they had also opposed the gas plant in Oakville.

“A decision was made that was agreed to by all the parties of the legislature,” Wynne said. “We implemented it.”

Wynne is scheduled to appear at the Standing Committee on Justice Policy at 3 p.m. Tuesday.