Canadian leaders made their final push for votes one day before an election dominated by US President Donald Trump's policies but were rattled in the campaign's final hours by a deadly car-ramming attack in Vancouver.

Prime Minister Mark Carney, the Liberal Party leader, is favoured to beat Conservative leader Pierre Poilievre in Monday's vote, but polls show the race has tightened in recent days.

The prime minister briefly paused his campaign schedule on Sunday to address the nation after a driver ploughed into a crowd at a Filipino street festival on the West Coast, killing 11 people.

Carney, a 60-year-old father of four, teared up as he voiced support for those affected.

"Last night, families lost a sister, a brother, a mother, a father, a son, or a daughter," Carney said. "Those families are living every family's nightmare."

After cancelling an earlier event near Vancouver, the Liberal campaign said Carney would visit the city later on Sunday.

A 30-year-old man who police said had a history of mental health issues and previous interactions with law enforcement was in custody following the attack that injured dozens.

Poilievre, appearing alongside his wife at a church in the election battleground city of Mississauga west of Toronto, condemned the attack as a "senseless act of violence".

"Our hearts are with you today. All Canadians are united in solidarity with the Filipino community," Poilievre said.

The Vancouver attack briefly shifted the nation's focus away from Trump, whose trade war and threats to annex Washington's northern neighbour have outraged Canadians.

Polling consistently shows Canadians believe Carney, a former investment banker who also led the central banks of Canada and Britain, is the strongest candidate to take on Washington.

Since replacing Justin Trudeau as prime minister on March 14, Carney has sought to convince voters that his resume has prepared him to lead Canada through a trade war and respond to tariffs that are pinching key sectors like auto and steel.

Poilievre, a 45-year-old who has been in parliament for two decades, has worked to keep the focus on living costs that soared during Trudeau's decade in power. He argues that Carney would continue what he calls failed Liberal governance.

Public broadcaster CBC's poll aggregator on Sunday put the Liberals' national support at 42.8 percent, with the Conservatives at 38.8 percent.

As with US elections, national polling numbers may not predict a result.

When voting closes on Monday, Conservatives will closely watch the performance of the left-wing New Democratic Party (NDP) and the separatist Bloc Quebecois.

In past Canadian elections, strong NDP performances in Ontario and British Columbia and a good showing by the Bloc in Quebec have curbed Liberal seat tallies, but polls suggest both smaller parties could be facing a setback.