TORONTO — The Conservative government's latest series of attack ads are unfair, dishonest and a sure sign that the federal Tories are ramping up for a federal election, Liberal Leader Stephane Dion said Monday during a campaign-style visit to a child-care centre.

The French and English commercials, which hit the airwaves last week, are bathed in Liberal red and target Dion directly, as well as former finance minister Ralph Goodale.

Dion called on Prime Minister Stephen Harper to withdraw the spots, one of which associates Dion with the sponsorship scandal and maligns him as weak and indecisive.

"He should do the honourable thing and withdraw these very, very negative ads that are so unfair,'' Dion said.

"If he's an honourable man, he will do the honourable thing.''

Dion said he would rely on the "intelligence'' of Canadians to evaluate the negative Tory tactics.

"They will reject this way to do politics and they will much prefer my approach, which is a positive one, (an) optimistic one,'' he said. "I will never do that.''

Dion's own itinerary Monday was as clear an indication as any that an election is in the air: he read a story to a group of toddlers and their parents at a multicultural west-end community centre, where he assailed the Tories for scrapping the former Liberal government's $5-billion child-care program.

"The link between the economy and social justice in Canada is something that we will make very, very clear over the next weeks and months,'' he said.

"If there is an election, it is very clear that we will campaign on it very strongly.''

Dion accused Harper of paving the way for a vote with a string of recent spending announcements the minority Conservative government has made in the past three months.

Most of the announcements --  worth as much as $10 billion, according to one tally -- were made to "correct'' the government's own spending cuts, especially to the environment and more specifically to climate change, Dion added.

The former environment minister, who was elected Liberal leader two months ago, acknowledged that his party has moved to an election footing.

"We have no choice other than to be ready at any time and we will be ready to offer to Canadians a very optimistic, ambitious vision for our country and a good action plan to make it through.''

Dion was particularly critical of a Conservative party TV ad that links Goodale to a 2005 leak about the government's tax plans for income trusts.

The leak prompted an RCMP investigation, which was announced in the middle of the last election campaign -- much to the embarrassment of former prime minister Paul Martin.

The probe did not link Goodale to any leak.

"Mr. Goodale is an honest man,'' Dion said. "He should not be attacked for something he never did.''