Progressive Conservative Leader John Tory nabbed the spotlight early on with a pledge to replace and refurbish the province's aging nuclear stations, accusing the incumbent Liberals of a "politically driven" energy plan that won't meet the province's needs.
Meanwhile, NDP Leader Howard Hampton promised to create a non-profit, northern Ontario hydro corporation to help the province's battered forestry industry, blaming job losses on the Liberals' failure to stop soaring hydro rates that Hampton said have debilitated local mills and plants.
Speaking at a campaign stop in the southwestern Ontario town of Tiverton, Tory said the province needs to re-examine its energy mix in order to meet the growing demand for electricity.
"We have to get moving on building new generating capacity in this province," he said, with the privately-operated Bruce A nuclear power plant looming large behind him.
"This means more renewable and alternative sources, but it also means a renewed commitment to nuclear energy."
Details of the Conservative plan were scant.
Tory wouldn't say how much nuclear power the province should have or how he planned to dispose of the radioactive waste, only that he would look at all the options and consult with experts first.
The Liberals and Conservatives both see nuclear as providing the baseload of power generation for the province, with dirty coal-fired plants being phased out by 2014. Currently, nuclear power generates about half of Ontario's electricity.
But it was Tory's suggestion that the lengthy environmental approval could be sped up without compromising its effectiveness that drew quick criticism from his opponents.
Environmental assessments are done by the federal government and obtaining approval for a new plant can take between seven and 10 years, Liberal Energy Minister Dwight Duncan said.
"(Tory) is talking about speeding up a process over which he has no control," he said. "Is he really proposing that the environmental assessment process for new or refurbished nuclear be circumvented? He obviously doesn't understand how (the assessment) works."
Premier Dalton McGuinty, who was in Toronto to unveil a $10-million pledge for Ontario athletes, acknowledged that nuclear power was necessary, but said his party would "drive hard" on renewable sources of energy.
"We need to have a healthy mix of generation, and part of that necessarily has to be nuclear capacity."
"(We're) going to drive hard on conservation, natural gas, expand our hydro electric capacity," he said. "But, at the end of the day, if we're going to be reasonable and thoughtful, we still need some nuclear generation."
The Liberals initially promised to close Ontario's coal plants by 2007, despite warnings that it couldn't be done. They since pushed the closures back several times when it became obvious alternatives were not going to be in place, eventually writing the 2014 closures into regulation this summer.
The New Democrats, who oppose the construction of any new nuclear power plants, said Tory and McGuinty are singing the same tune.
"(They are) promising environmental protection, then ignoring environmental laws and dumping billions into dangerous and unreliable nuclear power," the party said in a release. The Green party has pledged to ban the construction of nuclear reactors and phase out coal-fired plants.
Tory said he is optimistic that a mix of private and public power, including nuclear, is best for the province.
Having private operators run Ontario's nuclear facilities has been a "great success," he said.
"I think a mix is appropriate, where we could have private operators do what Bruce Energy had done, with that kind of a model where they come in and actually operate some of these facilities," he added. "But I still think the major role is for public power in Ontario. It's worked well for us and I think it will work going forward."