Justin Trudeau's future as the Canadian prime minister is looking increasingly shaky

• Canadian Prime Minister Justin Trudeau suffered another setback.
• His Liberal Party lost a Parliament seat that it had held for most of the last century.

Canadian Prime Minister Justin Trudeau suffered a new setback this week after his party lost a Parliament seat it had held for most of the last century.

Trudeau's Liberal Party lost in the Montreal parliamentary constituency of La Salle-Émard-Verdun against the Bloc Québécois, according to final results released early on Tuesday.

Liberal candidate Laura Palestini lost against Bloc Québécois' Louis-Philippe Sauvé by a 0.8% margin, with 27.2% of the votes against 28% for her opponent. NDP candidate Craig Sauvé came in third place.

It was one of the closest three-way contests in recent memory that saw the frontrunners switch positions throughout the count, according to CBC.

It's also Trudeau's party's second consecutive by-election defeat in less than three months, a result that will likely pile pressure on the Prime Minister to step down.

Trudeau already faced calls from his party to step down after losing Toronto-St. Paul — a safe seat in midtown Toronto that Liberals had held since 1993 — to the Conservatives in a byelection in June, per CTV News.

For the past year, the Liberal Party has polled well behind the Conservative Party at the federal level, now standing at 25% against 43% for the Conservatives.

An Ipsos poll conducted between September 5 and 9, 2024, put his approval rating at 33%. Two-thirds of Canadians disapproved of his leadership, citing disappointment with the cost of living and housing crisis.

His Conservative rival, Pierre Poilievre, meanwhile, was the favorite pick for prime minister at 45% against 26% for Trudeau.

Last Friday, Trudeau told Montreal radio station CJAD 800 that he would not resign if his party lost the LaSalle-Émard-Verdun election and vowed to stay on as party leader until the next election in October 2025.

Before the election results came out, longtime Liberal supporter and strategist Andrew Perez said another defeat would be "yet another nail in Justin Trudeau's coffin."

"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," he said in an X post on Tuesday.

"It's going to be really hard for them to get around the narrative that the government is basically done," Lori Turnbull, a Canadian political analyst and professor at Dalhousie University, told Politico.

Whether Trudeau's government will stay in power until the next federal election remains unclear.

Conservative Leader Pierre Poilievre has pledged to put forward a no-confidence motion against Trudeau's government "at the earliest possible opportunity" when Parliament reconvenes in an effort to trigger a federal election, per CBC.

However, Poilievre would require the backing of the New Democratic Party (NDP) and the Bloc Québécois to trigger an election — and it's unclear whether or not either party will join the motion, per CBC.