With questions swirling about his future, Trudeau largely stays on message in speech to donors

In his first address to party faithful since Monday's byelection loss, Prime Minister Justin Trudeau acknowledged the defeat but didn't seem to waver from his usual message.

"We have a time where people are facing huge challenges and huge uncertainty around the world. We saw that on Monday night in Toronto-St. Paul's," Trudeau told Liberal supporters at a fundraiser with Liberal donors in Brampton, Ont., on Thursday evening.

It's the first time he has been in the vote-rich Greater Toronto Area since his party lost Monday's byelection in what was previously considered a safe Liberal riding.

Liberal candidate Leslie Church lost in Toronto-St. Paul's to the Conservative's Don Stewart after the Liberals held the riding for more than three decades.

Still, on Thursday, the prime minister repeated a similar refrain from the past months: that the Liberals are focused on finding solutions while accusing the Conservatives of stirring up anger. But he also appeared to rally the spirits of those gathered following the beyelection loss.

"When that next election rolls around, everyone starts … with zero MPs. Everyone starts that election with zero votes," he said.

Trudeau received a standing ovation from the roughly 100 Liberal supporters in attendance, but otherwise the mood in the room appeared subdued.

The loss in Toronto-St. Paul's has fuelled conversations inside the Liberal caucus about the future prospects of the party, the tenability of Trudeau's leadership and the effectiveness of the political team that surrounds the prime minister, sources have told CBC News.

On Thursday, Liberal MP Sophie Chatel dodged a question about whether she thinks Trudeau should stay on as leader.

"It's not something that I feel comfortable to share. I think it's discussions that are being done internally. I think ultimately it's his decision, and I respect that," she told CBC News during a media availability.

Avtar Minhas, a Liberal supporter who attended Thursday's fundraiser, said Trudeau still has his support and said it would be a "very big setback" if the prime minister were to step down.

"He's very capable of winning still, I believe," Minhas told CBC News.

Bill Adair, another supporter who attended the fundraiser, shrugged off the Toronto-St.Paul's loss.

"It's one byelection, it's one riding," he said. But he seemed unsure about whether Trudeau should stay or go..