Tory says the scrubbers will remove 90 per cent of pollutants that cause health problems and lead to premature deaths in the province.
But critics say scrubbers do little to remove greenhouse gases that contribute to global warming.
"Putting scrubbers on coal plants is like putting a filter on a cigarette. It's still dirty and it's still deadly," Liberal Energy Minister Dwight Duncan said in a statement.
The Liberals have been harshly criticized for breaking a 2003 election promise to close the Nanticoke plant by 2007. The government twice put back the date until settling on 2014.
"(McGuinty) promises to protect those lives lost because of dirty air. He said he would do it ‘come hell or high water.’ So here we stand, in 2007. The coal is still burning," said Tory.
The Conservative leader added that he has no lessons to learn from a Liberal party whose negative campaign has turned into a "train wreck."
Experts say it could take 18 months to two years to put scrubbers on four of the eight units being used at the Nanticoke plant.
The Progressive Conservative leader said the electricity generated by the Nanticoke plant and the other coal-fired plants is needed by Ontario now. He said Nanticoke alone generates enough electricity to power nearly 2.5 million homes each year.
"We can't turn the coal plants off until we replace the power they generate, but for the sake of people's health and the air we breathe, we cannot afford to do nothing."
Estimates show that some 1,900 Ontarians die prematurely each year as the result of polluted air.
NDP Leader Howard Hampton said Tory's plan to spend money on scrubbers makes no sense.
"Nanticoke needs to be closed as soon as possible. We think we could close Nanticoke by 2011 by having an aggressive energy-efficiency strategy," Hampton told reporters at a campaign stop in Rexdale.
"If you're going to close them by 2011 scrubbers don't make sense."
Keith Stewart, manager of the climate control campaign for World Wildlife Fund-Canada, said $1.3 billion would be better spent on conservation and renewable energy.
"Scrubbers won't do anything to reduce greenhouse gas emissions," he said.
Phasing out Ontario's coal plants is expected to provide the largest share of greenhouse gas reductions in the near future. The Ontario Government's 2007 Action Plan on Climate Change relies on the coal phase-out for to provide at least 44 per cent of greenhouse gas reductions by 2014 and at least 29 per cent of reductions by 2020.