Four years after promising not to raise taxes, Liberal Leader Dalton McGuinty made the same pledge to Ontarians.

McGuinty's signed the Taxpayer Protection Pledge four years ago today during the 2003 election campaign.

He broke the no-tax promise the following year when the province was faced with a $5.6 billion deficit. Instead, McGuinty introduced the health-care levy that costs working Ontarians $900 each and was the single-largest tax increase in the province's history.

Progressive Conservative Leader John Tory reminded voters of the broken tax promise on Tuesday.

"This is a person who either made the promise without thinking about it, which is an indictment of his judgment and leadership, or kept repeating the promise knowing full well he was not going to keep it, which is equally an indictment of his judgment and leadership,'' Tory said while in Toronto.

"Dalton McGuinty not only broke his promise not to raise taxes. He shattered it beyond any recognition.''

Tory commemorated the anniversary of the signing with a visit to the Canadian Taxpayers Federation where he produced the original pledge.

John Williamson, head of the Canadian Taxpayers Federation, said McGuinty is a "liar'' who can't be trusted.

"This is a guy who four years ago said he wasn't going to raise taxes so if he says it again, it doesn't mean a whole lot,'' he said.

Province won't need new taxes

McGuinty said Tuesday he wouldn't be inking any new tax pledges but did say he doesn't expect taxes to increase if the Liberals win the Oct. 10 election.

"We won't have to increase taxes on a go-forward basis because we now know that we've come a long way from that $5.6-billion deficit,'' McGuinty said.

"We've balanced the budget two years in a row.''

McGuinty said instituting the health-care tax was the hardest political decision he's had to make, but said he stands by the levy.

"I had a very difficult decision to make. The choice I had was to make cuts to public services like health care or to invest in our public services like health care," McGuinty said while visiting an elementary school in the riding of Ottawa South on Tuesday.

"The decision I made, and it wasn't an easy one, was to ask Ontarians to invest in our health-care system."

NDP Leader Howard Hampton again dodged reporter's questions regarding his party's campaign promises while speaking at a York Region centre for autistic children.

Hampton said the details of his platform and the costs would be revealed within the next couple of days.

The NDP leader instead attacked McGuinty's promise-keeping record, focusing on his pledge not to increase funding for autistic children in the province. Hampton also criticized the spending of $2.4 million to fight the parents of autistic children in court -- an amount the Liberal government tried to keep from the public.

Later in the day, Hampton challenged McGuinty and Tory to a debate in northern Ontario, an area Hampton says is sorely over looked by the province.

"The situation in northern Ontario is so serious in terms of the loss of jobs, in terms of things like shortage of physicians, in terms of the outmigration of young people because they no longer see an opportunity,'' Hampton said.

"What I think what we really need to have in this campaign is a debate in northern Ontario about northern Ontario.''

With a report from CTV's Paul Bliss and files from the Canadian Press