The vote showed a deeply divided country with the defeated Conservatives winning the popular vote, while a resurgent separatist Bloc Quebecois made big strides in the mainly French-speaking province of Quebec.

The Liberals had won or were leading in 156 out of 338 seats in Monday's vote, according to Elections Canada, putting them far short of the 170 seats needed for another majority government.

"You did it, my friends. Congratulations," Trudeau told supporters in Montreal early on Tuesday.

Trudeau, who took power in 2015, saw his popularity drop over old photos of him in blackface and his handling of a corporate corruption case.

He will now have to rely on the New Democratic Party (NDP) to push through key legislation.

Although the NDP had a disappointing night, with the 24 seats it had won or was leading in down sharply from the 2015 election when it won 44, the party could exercise significant influence over Trudeau's next government.

NDP leader Jagmeet Singh said he had told Trudeau his party would work hard "to deliver on making sure we deliver the priorities that Canadians have".

Opinion polls showed a tight race between Trudeau and his main rival, Conservative leader Andrew Scheer.

"Tonight we have put him on notice," Scheer said in Regina, Saskatchewan.

"His leadership is damaged and his government will end soon and when that time comes, we will be ready and we will win.

"We are the government in waiting," added Scheer, 40, whose party won 122 seats.

Trudeau, 47, who has championed diversity as prime minister, was endorsed by former US President Barack Obama but the son of the late Liberal Prime Minister Pierre Trudeau also had to overcome a sense of fatigue with his government.

US President Donald Trump, whose relationship with Trudeau has been testy at times, congratulated him "on a wonderful and hard fought victory" via Twitter.

The Bloc Quebecois saw its support jump in Quebec, the only place where the separatist party contests elections.

It was elected or ahead in 32 seats, more than three times what the party won in 2015.

"Dear Quebecers, I heard your message tonight," said Trudeau, who also addressed voters in two western provinces where Liberals were shut out of seats.

"To Canadians in Alberta and Saskatchewan, know that you are an essential part of our great country. I've heard your frustration and I want to be there to support you. Let us all work hard to bring our country together."

The Greens, who have assailed Trudeau for not doing enough to combat climate change, also made gains.

Two Liberal cabinet ministers lost their seats in western Canada, where anger at Trudeau has mounted over federal environmental policies that the energy industry says will harm output.

Canada's economy, however, has been on a general upswing in 2019.

The liberal image of Trudeau took a severe blow during the six-week campaign when pictures emerged early in the campaign of him wearing blackface in the early 1990s and in 2001.

Trudeau had already been wrestling with the fallout from accusations he pressured his justice minister to help shield engineering firm SNC-Lavalin Group Inc from corruption charges.

In August, a top watchdog said Trudeau breached ethics rules.

Scheer, who promised to balance the federal budget and eliminate a "carbon tax" on fossil fuels, also proved to be a determined opponent.

Australian Associated Press