GUELPH, Ont. - Ontario Premier Dalton McGuinty lowered the temperature Thursday on his war of words with his former provincial foes in Ottawa, but wouldn't cede to federal charges that his refusal to give tax breaks to businesses is deepening Ontario's economic woes.

"I've been through three prime ministers now," McGuinty said after a visit to a Catholic high school in this southwestern Ontario city an hour's drive west of Toronto.

"Federal governments come and federal governments go. We don't really have any permanent allies or permanent enemies, just permanent interests."

McGuinty's attempt to ratchet down the rhetoric followed an ugly exchange of words between a member of his cabinet and federal Finance Minister Jim Flaherty over different approaches to stimulating economic growth.

On Wednesday, Ontario's Economic Development Minister Sandra Pupatello called Flaherty a "cartoon character" and accused him of "bald-faced lies" after he slammed the provincial Liberals for a "lack of leadership and vision" in dealing with the province's struggling economy.

Name-calling between the Conservatives and Canada's largest province is nothing new; McGuinty was labelled the "small man of Confederation" by Conservative House Leader Peter Van Loan last month for complaining about a proposal to redistribute House of Commons seats.

Wednesday's nasty turn between Pupatello and Flaherty seemed to signal a renewal of old hostilities that date back to Ontario's previous Conservative rule.

Flaherty, a former Ontario finance minister, is among a number of ex-provincial Tories who were elevated to Prime Minister Stephen Harper's cabinet after the 2005-06 federal election.

But McGuinty refused to be dragged into the insult game Thursday after touring a robotics program at Our Lady of Lourdes Catholic High School.

"If Mr. Flaherty is a cartoon character, which one is he?" one reporter asked.

"I'm not touching that," McGuinty replied.

The premier insisted, however, that he'll do what he thinks is necessary to stand up for the province, which he acknowledged is going through a "challenging" period.

But more could be done if Ottawa lent its support, he added.

"The point that I'm making to the prime minister is that I think it's no longer acceptable to say, all you need to do is cut taxes and stand back and . . . economic evolutionary forces are going to play themselves out," McGuinty said.

"Because I've been to China, I've been to India, I've been to Japan, I've been to Switzerland and I've been to parts of the U.S., I've been to parts of Europe and in all of those cases, government comes to the table and says, 'How can I help?"'

Not all experts agree that direct government help to the hard-hit manufacturing sector will alleviate the province's current troubles.

"We would be fighting a losing battle - given all the international evidence that this is a common experience across the industrialized world - if what we tried to do was to prop up some of these manufacturing jobs by playing the subsidy game and pouring billions of dollars worth of expenditures in trying to retain those jobs in the short run," said RBC assistant chief economist Derek Holt.

"No matter what you do, I think some of those jobs are just going to disappear in any event."