Canadian Prime Minister Justin Trudeau says he's focused on the work ahead after the ruling Liberals lost in another by-election, raising more questions about his ability to lead the party into the next federal election.

Doubts about the leadership of Canadian Prime Minister Justin Trudeau intensified after his ruling Liberal Party suffered a second humiliating loss in a special election, but the unpopular leader is determined to cling to office ahead of a looming national vote.

Prime Minister Justin Trudeau's Liberal Party has lost a crucial parliament seat in a special election in Montreal, a defeat likely to put more pressure on the Canadian leader to quit. The narrow loss in Montreal's federal electoral district of LaSalle-Émard-Verdun is the second such defeat in three months for Trudeau's minority Liberal government.