Meanwhile, Conservative leader Poilievre made his final stops in Ontario where polls indicate his party is trailing behind. The populous province is home to 122 seats in Parliament out of 343 that could alter the outcome of the election. A party must win 172 seats to have a majority government. The Liberals currently hold 152 seats, the most of any party, but they would have to pick up a significant number of seats to control the House of Commons.

Much of Poilievre's messaging has centred on what he has called the "lost Liberal decade" under the leadership of former Prime Minister Justin Trudeau, who stepped down earlier this year when his party was ailing in the polls.

The Conservative leader frequently drew upon frustrations with soaring housing costs, unaffordability and crime to pitch himself as the change that Canadians need.

"We need to vote for change so you can afford food and homes," he told supporters at a campaign stop in Peterborough, a city north-east of Toronto.

And with the election shaping up as a race between the Conservatives and the Liberals, smaller parties have struggled to gain traction.

The left-leaning New Democratic Party (NDP), led by Jagmeet Singh, faces the prospect of losing a number of seats as it trails behind the separatist Bloc Québécois, which runs candidates only in the French-speaking province of Quebec.

Singh cancelled a number of campaign events on Sunday in light of the deadly attack in Vancouver. The NDP leader, who is running for re-election in a Vancouver-area riding, was meeting supporters at the Lapu Lapu festival minutes before the attack. He appeared visibly emotional when he spoke to the media afterwards.

Throughout the election, Singh called on Canadians to vote for his party's candidates so they can act as a check on power in Ottawa.