Liberal Leader Justin Trudeau took aim Monday at a government he says has taken its loyal supporters for granted, speaking in the city considered to be the home base for the Conservative Party.

The Conservative Party and its leader, Stephen Harper, have been making it clear they see the economy as the most important factor when Canadians decide how to cast their ballots on Oct. 19. Trudeau attacked their fiscal record directly.

"With friends like Stephen Harper, the Alberta economy doesn't need enemies," Trudeau said.

"He let you down. He let us all down."

The Canadian economy recently recorded its fifth consecutive monthly contraction in gross domestic product, while the parliamentary budget officer is predicting a small federal deficit at the end of the year based on those low GDP numbers.

The Conservatives have called the Liberals and NDP both "reckless" and "risky," comparing their economic policies to those of European countries with far weaker economies than Canada's.

Harper reassured a Laval, Que., audience about the Canadian economy Monday morning, telling them the recent numbers are a result of "temporary effects" due to lower oil prices.

"Analysts are predicting good growth for the country into the future as long we stay on track."

Justin Trudeau has made regular trips to Calgary since he became the Liberal leader in 2013, including during the Calgary Stampede last month. (Jeff McIntosh/Canadian Press)

On Monday night at a rally in Ajax, Ont., Harper fell back on one of the party's favoured 2011 campaign slogans, calling for a "strong, stable, majority Conservative government."

Well-practiced attacks

But after spending months, if not a year or more, anticipating the election, the attacks are well-practiced, and all the leaders can anticipate each other's key arguments.

"When the plan isn't working, the real risk is sticking with the status quo," Trudeau said.

The Liberal leader zeroed in on the economy and the oilsands, arguing there hasn't been a single major pipeline built under the Conservatives, and that Harper has antagonized the U.S. over the Keystone XL pipeline extension.

"Instead of a better future for Alberta's energy industry, Harper's divisive diplomacy pitted western Canada against everyone else, including our American allies," Trudeau said.

Conservative Leader Stephen Harper focused on the economy Monday, saying Canada is still doing better than its G7 counterparts in long-term economic growth. (Christinne Muschi/Reuters )

"You are tired of being taken for granted by a government that is focused more on itself than on you. That spends your money on themselves to buy an election instead of investing it in you to make your lives better."

Harper was born and raised in Toronto, but has spent three decades in Calgary and is running for re-election in the new riding of Calgary Heritage.

Trudeau was in the Calgary Confederation riding, one of the few ridings in the Alberta city with no incumbent candidate due to newly drawn boundaries. Liberal candidate Matt Grant and Conservative Len Webber will face off on Oct. 19 to represent the area. The NDP hasn't yet nominated a candidate in the riding. Natalie Odd is running for the Green Party in Calgary Confederation.

The federal NDP has been buoyed by the provincial party's recent election in Alberta, which had seen only Progressive Conservative governments for decades, although the federal party has so far nominated only six candidates in the province.

But the Liberals have set their sights on several seats there, and Trudeau has paid particular attention to visiting the province since he became the Liberal leader in 2013.

Trudeau first leader in Alberta

Grant is a lawyer who has worked in the past for provincial Liberal politicians, including fellow federal Liberal candidate Kent Hehr, who is running in Calgary Centre. Webber is a former PC member of the legislative assembly.

Harper kicked off his campaign Sunday night in Quebec, the political backyard of Trudeau, who holds the riding of Papineau.

Harper held his first campaign rally in the Montreal riding that Trudeau's father represented when he was prime minister. The Conservative campaign then moved to the nearby town of Laval, where Harper pledged to extend and increase an existing credit to help employers hire apprentices.

Mulcair made a brief statement Sunday, where he took no questions, and then attended the funeral of former foreign affairs minister Flora MacDonald, but didn't campaign Monday. He is heading to Montreal on Tuesday.

Trudeau is returning to Ontario Tuesday morning to campaign in Mississauga, Ont.

Green Party Leader Elizabeth May will spend Tuesday travelling to Toronto from her Victoria, B.C.-area riding of Saanich-Gulf Islands.

Harper, Mulcair, Trudeau and Green Party Leader Elizabeth May will be in the Toronto area Thursday for the first leaders' debate of the campaign.