Conservative Leader Stephen Harper capped off a hectic Saturday of campaigning in Ontario and Quebec by giving a fiery speech at a much-discussed rally promoted by Toronto's Ford brothers.

Both Rob Ford, the former Toronto mayor who admitted to using crack cocaine while in office, and his brother Doug attended the event at the Toronto Congress Centre in the suburb of Etobicoke.

Harper appeared energized by the crowd of about 1,200 people, thanking campaign volunteers, including the Ford family and driving home his usual points on the economy and the threat of a Liberal government.

"The Liberals stick to a few slogans. They talk very little about the details of their platform," he said, warning of tax raises should Justin Trudeau win on Monday.

Doug Ford — who riled up the crowd before Harper's speech — took the threat one step further, blasting the Liberal leader and his affiliation with "mentor" Ontario Premier Kathleen Wynne.

Doug Ford points out his brother Rob Ford, slams Justin Trudeau at Conservative rally 2:14

"Make no mistake, God help this country. It would be an absolute disaster if Justin Trudeau and Kathleen Wynne were running this country," Ford said to big cheers.

The Fords have been campaigning heavily for the Conservatives, sitting in the front row at an event earlier in the week in Etobicoke and heavily publicizing Saturday night's rally.

Harper mentioned the Fords at the rally's onset and even posed for a photo with them, which was posted to Rob's Twitter account.

Harper has come under fire this week for associating with the Fords while campaigning on a platform of law and order. He was asked about his party's association with the Fords earlier Saturday, but avoided the question.

Thank you <a href="https://twitter.com/pmharper">@pmharper</a> it was great to see you tonight & thanks to the thousands of people who came <a href="https://twitter.com/hashtag/elxn42?src=hash">#elxn42</a> <a href="https://twitter.com/hashtag/elxn2015?src=hash">#elxn2015</a> <a href="http://t.co/tqIxs0inxD">pic.twitter.com/tqIxs0inxD</a> —@TorontoRobFord

"This campaign, our Conservative campaign, from one end of the country to the other, including in the great area of Etobicoke which I grew up in as a teenager, is about making sure we keep our economy," Harper told the crowd.

While Harper stuck mostly to his usual script during the Toronto rally, there was a surprise appearance during game-show-like routine with the cash-register sounds: Harper brought out the man who said the lines "Nice hair, though" in the Tory attack ad criticizing Trudeau.

Stops in Laval, Oakville

Earlier in the day, the campaign made stops in Laval, Que. and Oakville, Ont.

In Laval, Harper spoke before a boisterous crowd of about 1,000 supporters and stayed tightly on message as he fielded questions from reporters about his political future.

CBC News's Susan Lunn, characterizing Harper as the "architect of the modern Conservative Party," posed a reflective question.

Conservative leader Stephen Harper won't explain why he's including former Toronto mayor Rob Ford in campaign events. 1:05

"No matter what happens on Monday, what kind of future do you see for the party you created going forward?"

Harper, pausing for a moment with a smile, answered first in French, then English.

"I could not be more honoured to be the prime minister of the greatest country in the world, it's always an honour," he told the cheering crowd.

"In the past 10 years I believe our Conservative party has led this country forward during a difficult time, to be more prosperous, more united, more proud, more secure than ever before," he added.

Harper was also asked about how significant it was that his chief opponent is Liberal Leader Justin Trudeau, the son of former prime minister Pierre Trudeau. The reporter prefaced the question by saying Harper's opposition to the elder Trudeau's policies were what helped propel the Conservative leader into politics.

Without skipping a beat, Harper responded that he "always said that Justin Trudeau deserves to be judged on his own merits."

"The reality in this election is that the Liberal Party is running on a platform that would spend an additional $150 billion," he said. He contrasted the Grits' plan for deficits with the Conservatives' focus on balanced budgets, low taxes and job creation.

The attacks on the Liberals continued during a brief stop in Oakville.

"Friends, it will be just like the Liberal government in Ontario," he warned the crowd, who booed at the reference to Ontario Premier Kathleen Wynne's Liberals.

"We cannot afford to have that at the national government of this country."