If Ontario Premier Kathleen Wynne does not call a public inquiry into the costly cancellation of two gas-fired electricity plants, the legislature will "become seized" with the scandal, New Democrat leader Andrea Horwath said.
The Liberal government had earlier rejected calls for an inquiry, saying such a proceeding would be too expensive. But Ms. Horwath kept the pressure up Friday, a day after the controversial subject exploded again with the release of fresh documents on the mothballing of the plants.
"It's obvious that this is one steaming mess that needs to be looked at with a separate, unbiased set of eyes," she said.
The scandal tied up Question Period Thursday, and Ms. Horwath warned the government to expect more of the same if it did not set up an independent commission to investigate the issue.
Despite the revelations, however, Ms. Horwath said her party would still support the government in a confidence vote on the Throne Speech.
The government put the brakes on the plants, in the Toronto suburbs of Mississauga and Oakville, before the 2011 election in what was widely seen as a ploy to save Liberal seats in that vote.
Last year, at the behest of the opposition, the government began releasing documents related to the cancellations. But on two occasions, the Ontario Power Authority missed papers that were supposed to have been released.
Among the 592 pages revealed Thursday were emails that said David Livingston, who would later be appointed then-premier Dalton McGuinty's chief of staff, was leading the talks to relocate the Oakville plant.
An OPA official also conceded that the agency would have built the Mississauga plant had it not been for interference from politicians, and that the cost of the plants could exceed the $230-million figure the government has previously cited.
He also acknowledged that the OPA knew as far back as October that it might have missed releasing some documents.
Ms. Horwath said a public inquiry is necessary to learn why the legislature was not informed until this week that more documents were coming. She also accused the premier's office of withholding files on the scandal.
The NDP and Progressive Conservatives already teamed up earlier this week to have a parliamentary committee investigate whether documents had been deliberately covered up.
A public inquiry, however, would entail wider-ranging hearings that could prove damaging for the Liberals by keeping the scandal in the public eye for months.