Testifying under oath before the legislature's justice committee, McGuinty acknowledged that he was the one who made the decisions to scrap the planned gas plants in Oakville and Mississauga, bowing to the wishes of local residents.
"In my office, we don't have the capacity to make calculations associated with these kinds of contractual arrangements, or to make these kinds of estimates as to what ultimate costs might be," he told the committee.
"I knew that going into this, that when I said we're going to relocate gas plants, that I did not have at my hand the costs associated with that."
The estimated cost of cancelling the two energy projects and relocating them in Napanee and Lambton has soared to at least $585 million, far above the $230 million McGuinty and the Liberals had been claiming.
McGuinty refused to acknowledge the opposition's charge that the gas plants were cancelled just to save Liberal seats, and insisted all three parties had made promises to scrap the energy projects, not just the Liberals.
The gas plants were too close to homes and schools, said McGuinty, and wouldn't have cleared new rules used to keep giant wind turbines at least 550 metres away from residential neighbourhoods.
"We were faced with a circumstance where gas plants were sited right next to schools, condominium towers, family homes and a hospital. That wasn't right," he said.
"Moving two gas plants cost more than any of us would have liked, and in return for the next 20 years children won't be going to a neighbourhood school in a shadow of a smokestack."
Progressive Conservative energy critic Vic Fedeli set the tone for the questioning by going on the attack after McGuinty said it was his decision to cancel the gas plants.
"I must say premier that while you may have masterminded the heist, your henchmen committed the crime and drove the getaway car," said Fedeli.
McGuinty and Fedeli clashed repeatedly, especially when the former premier kept insisting he didn't know cancelling the Oakville plant would cost hundreds of millions of dollars more than the $40-million figure the Liberals had been using. The latest estimate is at least $310 million.
"You keep saying that I'm not giving you an answer," complained McGuinty, "Perhaps you don't like the answer."
"No, no, I don't believe the answer," said Fedeli. "To be perfectly frank, I don't believe your answer."
McGuinty said he took too long to realize the people of Oakville and Mississauga were right to oppose the gas plants and his government was wrong to try and build them.
"What became apparent — at least to me — was that getting out of this was going to be complicated, and that there were going to be costs associated with that," he said.
"But I'd much rather be here today talking to members of this committee, rather than ducking the people of Oakville and Mississauga over the course of the next 20 years as we put in place gas plants which never should have gone in there."
NDP Leader Andrea Horwath called it "shocking" that McGuinty admitted that any price for cancelling the gas plants would have been OK by him, but said she didn't believe that he wasn't aware of the costs until very recently.
"I suspect he did know at least ballpark what those figures were, but unfortunately the former premier continues to stick to his old lines," said Horwath.
"The people of Ontario are the ones stuck with the bill and they're also stuck with a real sense of cynicism around a government's commitment to being accountable.
McGuinty admitted that halting construction on the partially built Mississauga gas plant just days before the 2011 election only added to voter cynicism.
"That creates real challenges politically, but it doesn't relieve us of the responsibility of doing what we honestly think is right," he told reporters after the hearing.
McGuinty also said he doesn't intend to resign as the MPP for Ottawa South until the next general election, even though he has only shown up in the legislature once since resigning last fall, for the vote on the minority government's throne speech.
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