Liberal Leader Justin Trudeau today acknowledged the Conservatives could win Monday's election — and accused the party of winning support by running one of the "dirtiest, nastiest" election campaigns in Canadian history.

Surrounded by 29 Quebec candidates at an event at Montreal's Botanical Garden Wednesday, Trudeau appealed to Quebecers to support his party and elect a progressive government rather than a "progressive opposition." It's a pitch he's been making a lot lately — a bid to beat down surging support for the NDP and Bloc Québécois by arguing that voting for those parties could help elect a Conservative government.

Asked about a report in The Globe and Mail about the Manning Centre refusing to disclose the source of donations to third parties for attack ads on the Liberals, Trudeau took the opportunity to take aim at Conservative tactics in the campaign.

"We know that the Conservative Party is running one of the dirtiest, nastiest campaigns based on disinformation that we've ever seen in this country," he said.

"And it's no surprise that they don't want to share whose deep pockets are funding their attacks on Canadians, on other parties and on the most important fight of our generation, the fight against climate change."

When asked if the Manning Centre should disclose where it is receiving funding to back a series of anti-Liberal Facebook pages, Liberal Leader Justin Trudeau accuses the Conservatives of running a campaign based on disinformation. 0:51

Trudeau said a Conservative government would be "truly unfortunate" for the fight against climate change. Calling it a "pivotal moment," Trudeau said the choice Canadians make on Monday could have consequences for generations to come.

"We could wake up next Tuesday with a government led by a new leader. And the only way to prevent that from happening is to vote for the Liberal Party, to elect our great Quebec team, from all regions of the province, who share your values and your priorities and who understand your issues," he said.

Pressed by reporters on whether he considers defeat a distinct possibility, Trudeau said he was making it clear that this is an election that matters deeply to Canada and beyond, and that he is not taking any votes for granted.

Conservative Leader Andrew Scheer, campaigning in southwestern Ontario, said his party is building steam in the final days of the campaign because Canadians don't want a "NDP-Liberal coalition, where the NDP will be calling the shots, but Justin Trudeau will be the spokesperson for it."

Scheer eyes majority

"NDP are calling for massive tax hikes, massive deficits that will threaten our economy, and mean more and more of your tax dollars goes to pay just the interest on that debt," he said. "So that is the crystal clear choice and I'm very confident that Canadians don't want an NDP-Liberal Coalition. They will vote for a Conservative majority."

During an event in Hudson, Que., NDP Leader Jagmeet Singh said he hasn't yet determined if this campaign was worse than others in tone, while saying a respectful campaign is something the parties should strive for.

"We can disagree, can have different opinions, but we should all agree to do it respectfully, but also to do it in a way that doesn't divide the population purposefully," he said.

"We can have different opinions and we can still seek to bring people together. But I also want to push back. Do not vote out of fear and don't let Mr. Trudeau encourage you to vote out of fear."

After blasting the Conservative campaign tactics, Trudeau was also was asked to defend his own party's campaign tactics.

Liberal Leader Justin Trudeau says Conservatives would tear up the climate policies put in place by the Liberal government. 1:12

A recent tweet from senior campaign adviser Gerry Butts used a photo of Conservative Leader Andrew Scheer shaking hands with a construction worker to try to tie Scheer to the "yellow vest" movement, which began in France and has spread to other parts of the world, including Canada. Movement participants in this country have protested against immigration policies, the carbon tax and the United Nations Migration Pact.

Trudeau dodged the question about the Butts tweet and accused the Conservatives of deploying the politics of fear and division.

"I think Conservatives need to continue to be called out for the nasty, negative campaign that they are running, because Canadians deserve better," he said.

Trudeau asked Quebecers to back the Liberal plan to fight climate change and said Conservatives would rip up the only national climate plan Canada has ever had.

"Canadians get that, but Quebecers get that particularly well," he said. "For the past 10 years, Quebec and B.C. have had a price on pollution. They've done more than their share."

Scheer has said his first act, if elected, would be to table legislation to scrap the Liberal carbon tax.