Prime Minister Mark Carney went head-to-head with Conservative Leader Pierre Poilievre during question period Monday as MPs returned to the House of Commons for its fall sitting for the first time since June.

In his opening remarks, Carney welcomed Poilievre back to the House, but the levity between the two didn’t last long as they engaged in heated debate.

Here’s everything that happened on Monday, Sept. 15, 2025.

2:50 p.m. EDT: Mulcair on how the leaders did

In his analysis of how the leaders fared in their first question period faceoff, former NDP leader Tom Mulcair said Prime Minister Mark Carney seemed to be caught off guard by the format a few times and stumbled when answering questions, specifically by how quickly he needs to formulate answers.

But he said he expects Carney to improve over time. He added that Conservative Leader Pierre Poilievre seemed to be holding back on the first day, judging from how he’s comported himself in the past.

One rookie minister whom Mulcair noted was impressive in his debut was Housing Minister Gregor Robertson, the former mayor of Vancouver. Despite his rookie status, Mulcair noted Robertson is also a seasoned politician, and “boy does it show when he stands up to give his answers.”

All in all, Mulcair said it was a “very interesting question period,” adding that there will surely be “lots more sparks in the days and weeks ahead.”