The man who helped orchestrate the Ontario Liberals' three election victories says he wasn't behind the party's decision to cancel gas plants in Oakville and Mississauga at a cost of at least $585 million.

Testifying at justice committee hearing on Tuesday, Don Guy said his role was to arrange the public announcement of Dalton McGuinty's decision, which was made by Liberal Charles Sousa, now Ontario's finance minister.

"The idea was in the premier’s head before the campaign started," Guy said, noting he had "one or two discussions on the phone" with McGuinty as he was close to making a decision about cancelling the gas plants.

The longtime chief of staff to former premier was grilled for two hours this morning by opposition MPPs who pressed Guy explain what he knew about the controversial decision.

"Was it you calling the shots?" asked Progressive Conservative MPP Vic Fedeli.

"Couldn't be further from the truth," Guy replied, maintaining throughout his testimony that it was McGuinty's decision alone.

Guy was also asked by opposition members about why the government was so slow to release all related documents requested by the estimates committee.

"Did you have any discussions about the non-release of documents?" said NDP MPP Gilles Bisson.

"I believe I heard about it in the media," Guy said.

"Were you involved in the discussion?" Bisson pressed.

"No," Guy said. 

The opposition parties call the cancellations an expensive Liberal seat "saver program," and the governing party did hold all five ridings in the area in the 2011 election.

Then-energy minister Chris Bentley initially said it was a Liberal campaign decision to cancel the partially-built Mississauga gas plant just two weeks before election day, but McGuinty later testified that it was his decision alone.

Recently released emails show the Liberals running in McGuinty's office wanted cabinet ministers to say it was the government that killed the gas plants, not the Liberal campaign team.

With files from The Canadian Press