Voters went to the polls in the Montreal riding as well as in Winnipeg's Elmwood--Transcona, where the NDP retained their long-held seat after a tough race against the Conservatives.

Trudeau already faced calls from party faithful to resign as leader after unexpectedly losing Toronto--St. Paul's to the Conservatives in a byelection this past June.

Longtime Liberal supporter and strategist Andrew Perez called the loss "yet another nail in Justin Trudeau's coffin."

While byelections aren't usually credited with much significance on Parliament Hill, the votes in Winnipeg and Montreal are being viewed as bellwethers of the political shifts happening in Canada.

"If Trudeau's Liberals can't hold this safe seat, it will spell even bigger trouble for the party's prospects in Quebec and across Canada in a critical election year," Perez said in a statement before the final vote.

Bloc Quebecois supporters in Montreal shouted and jumped up and down so hard the floor shook at news of their victory, some with Quebec flags draped around their shoulders.

The Bloc was locked in a tight three-way race with the Liberals and the NDP right up until the final poll was reported.

"We are here and we work hard because we believe in the interests of Quebec and we believe in independence," the Bloc candidate Louis-Philippe Sauve said before the final votes were counted.

Elections Canada reported all 187 polls early Tuesday, showing the Bloc won the seat just 248 votes ahead of the Liberals.

The Montreal seat opened up when former justice minister David Lametti left politics.

The Bloc's deputy House leader Christine Normandin said no one would have expected the Bloc to do well in the longtime Liberal stronghold at the start of the campaign.

"Any way the campaign would have gone, we could only win, we had nothing to lose," she said before the results were in.

"Seeing tonight that it is a tight race, in itself for us, it's a win. And it shows that there is support for what the Bloc does and the issues that we're bringing to the House of Commons."

The NDP also took heart from the tight race. The New Democrats are not usually a contender in the Montreal riding of LaSalle--Emard--Verdun, but their candidate, Craig Sauve, jockeyed back and forth for first place with the Liberals and Bloc all night.

"If the NDP is competitive in Montreal we're going to win seats in Montreal, we're going to have great candidates in Montreal, and Montrealers are going to are going to see more NDP MPs at the next election," the NDP's candidate Craig Sauve told his supporters earlier in the night.

NDP Leader Jagmeet Singh is keen to leapfrog the Liberals and position himself as the only viable, progressive alternative to Pierre Poilievre's Conservatives.

He and his candidate, Leila Dance, managed to fend of the Conservatives' aggressive campaign in Winnipeg.

The Conservatives appealed to traditionally NDP voters on issues like labour and affordability in an attempt to sway the riding.

The NDP won the night with 48.1 per cent of the vote. But Conservative candidate Colin Reynolds managed to grow the Tories' share of the vote from 28 per cent in the 2021 general election to 44 per cent in Monday's byelection.

With several polls still to be counted, Reynolds conceded defeat and told his volunteers that they should be proud of what the Conservatives accomplished in the campaign.

This report by The Canadian Press was first published Sept. 16, 2024.