OTTAWA -- Stephen Harper and NDP Leader Tom Mulcair took aim at Justin Trudeau on Saturday as federal election campaign entered its final 48-hour sprint.

At a boisterous rally in Laval, Que., the Conservative leader said his Liberal rival was in charge of a party that has deficits in its DNA, and warned that change for the sake of change would hurt the economy.

Harper accused Trudeau's Liberals of "running on a platform that would spend an additional $150 billion that would be financed by cutting benefits we actually have, raising taxes, and running deficits, which means more benefit cuts and more raising taxes later."

Harper appeared to acknowledge polls that show Trudeau's Liberals leading in the campaign.

"I have to confess that I know the temptation for change might be strong. After all, we change cars, houses even jobs --and sometimes it's the right decision. But to imperil your financial future and that of your family, that's another matter," he said.

Harper also told his Quebec audience that one of the "worst examples of the public mismanagement of funds" was the sponsorship scandal involving Liberal-linked advertising firms in the province.

In British Columbia, Mulcair linked the Liberal sponsorship scandal to the revelation this week that Dan Gagnier, a member of Trudeau's inner circle, offered lobbying advice on an energy project.

"The wolf is just waiting for the gate to swing open to the sheep fold," he said. "So we shall fight until Monday to ensure that the people responsible for the sponsorship scandal -- the Liberal party -- never take power by forming the first NDP government in the history of Canada."

Bloc Quebecois Leader Gilles Duceppe also raised the sponsorship scandal Saturday in Sept-Iles, Quebec.

He said the Gagnier controversy shows the Liberal party hasn't "hasn't changed its shenanigans" since the sponsorship scandal era.

Campaigning in the Maritimes, Trudeau exhorted his followers to get out the vote on Monday to push Harper out of 24 Sussex once and for all. He told them to ensure that "no vote -- and no voter -- gets left behind."

With polls suggesting the Liberals have been leading, Trudeau found himself being asked about what he would do in the initial days of his mandate should he become prime minister.

He offered little new information, except when it came to which foreign leaders he might reach out to first.

"Over 10 years, Mr. Harper has soured our most important international relationship with the United States," Trudeau said. "I look forward to speaking with President Obama if I earn Canadians' trust on Monday to talk about the kinds of challenges we're facing on our continent."

Specifically, he mentioned the idea of efficient trade over a secure border and more generally, improving the relationship between two important friends and allies.

"We won't always agree on everything, obviously . . . but we do need to be able to talk openly and responsibly together, which Mr. Harper has been unable to do for the last 10 years."

In a blog posting Saturday, Green Leader Elizabeth May made an appeal against strategic voting that would push support towards Liberal or NDP candidates in certain ridings.

"I can only assume our friends do not understand that a Green MP will vote with Liberals or NDPers on confidence motions, making them an equally effective anti-Harper MP," she wrote.

"In fact, Greens are more effective in this respect since we prize co-operation above partisanship, so you can trust us to put Canada's interests above political gains."