By Lori Turnbull
November 6, 2025
First, in a Budget-Day bombshell, Nova Scotia Conservative MP Chris d’Entremont announced his decision to cross the floor of the House of Commons to join the Liberal government.
Two days later, on Thursday evening, Conservative MP Matt Jeneroux announced his decision to resign as a member of Parliament. In his statement, Jeneroux did not elaborate on that decision, but said he hopes “to have the opportunity to address the House one final time in the future.”
In the world of zero-sum politics, this has been a very big week for Prime Minister Mark Carney and the Liberals — especially Budget Day no less, when d’Entremont’s move reduced the government’s minority margin from three to two — and a devastating one for Pierre Poilievre and the Conservatives.
While, at this writing, Jeneroux’s departure and its implications remain to be fully unpacked, D’Entremont’s decision strikes a chord at a level that cuts much deeper than its effect on the party standings in the House of Commons – even with a budget vote at stake.
Floor-crossers — and there have been 300 of them since 1867 — break the cardinal rule of Canadian politics: party loyalty. An MP’s decision to switch caucuses is an act of personal and professional autonomy that threatens to disrupt the power that political parties are accustomed to holding. D’Entremont’s decision shows that party loyalty has limits.
Almost all MPs are members of political parties — even the rare independent ones usually start out that way. They act not as free agents or as autonomous lawmakers in their own right, but instead they act as part of a disciplined team.
In Pierre Poilievre’s Conservative Party, MPs are not only expected to vote on proposed legislation according to the party line, but there are also reports of them having their public comments scrutinized by the leader’s office. Hyper partisanship is encouraged. Conservative MPs have been discouraged from fraternizing with members of other parties. It was reported in 2024 that Conservative MPs felt “less free” than they did prior to Mr. Poilievre’s arrival as leader.
Perhaps it was easier for Mr. Poilievre to make these demands of MPs back when his path to victory seemed assured. But since he lost both the general election and his own seat in the spring and was forced to re-enter the House of Commons in a safe Alberta byelection, it seems the balance of power may be shifting and it is getting more difficult for Poilievre to command the loyalty of caucus members.
Poilievre’s comments in October about the leadership of the RCMP and his suggestion that his former political opponent Justin Trudeau ought to have been jailed caused palpable discomfort in his caucus — especially at a time when Canadians are watching Donald Trump prosecute his political opponents to settle scores. And the fact that Carney puts fiscal responsibility at the core of his political identity makes it easier for Red Tories like d’Entremont to find somewhere else to sit.
To be clear, MPs’ loyalty to their party is not just symbolic. Political parties provide support to candidates and elected members in the form of money, volunteer networks, and branding. It is common for MPs to feel that they owe their political success to the leader, whose brand has a determinant effect on the party’s success.
Most people vote for the leader or the party rather than the candidate, which can give the sense that the party “owns” the seat and the MP is replaceable. The party could have won without a particular candidate, but the reverse is rarely true.
People would be more inclined to think of his departure as a one-off if not for persistent questions about Mr. Poilievre’s political judgment.
Given all of this, when an MP decides to switch caucuses, it sends shock waves through the party they’ve left behind. There is a sense of defection, betrayal, and deception. Questions begin to swirl, such as: When did the member begin to contemplate switching teams? And what secrets might they share with their new colleagues?
There is an emotional hit when floor-crossing occurs because political parties are not merely professional groupings. They are a form of family whose members are brought together by shared values and experiences. An unexpected departure can make for hurt feelings which, as might be the case with some Conservatives in reaction to Mr. d’Entremont’s move, sometimes express themselves in accusations of treachery and dishonesty. It is not an easy time.
For their part, those who cross the floor are motivated by a combination of two main factors: values and self-preservation. The relative weight of each of these variables depends on the circumstances and the people involved.
For example, Scott Brison’s decision to cross the floor to the Liberals following the merger of the Canadian Alliance and the Progressive Conservatives was understood to be motivated primarily by values, principles, and the need for political alignment. Brison is gay and the newly merged Conservative Party did not support gay marriage. His party left him rather than the other way around.
In stark contrast, Eve Adams’ eyebrow-raising migration from the Conservatives to the Liberals in 2015 smacked of nothing but opportunism and the desire to save herself from political defeat. In the end, the Liberals’ commitment to her was equally fragile as she did not even manage to secure a nomination to run for the party in the 2015 election.
There is every reason to think that Chris d’Entremont was motivated both by political survival and the desire for values alignment. He won his riding by only 533 votes in the spring election, with the Liberal candidate nipping at his heels. Switching jerseys is a smart political play.
On the values side, there is no doubt that d’Entremont can feel comfortable sitting alongside Mark Carney. If history had worked out differently and there was still a Progressive Conservative Party in Canada’s House of Commons, it is easy to imagine both individuals in its caucus.
Ottawa is now rife with speculation about whether other Conservative MPs will follow d’Entremont to the Liberal caucus. People would be more inclined to think of his departure as a one-off if not for persistent questions about Mr. Poilievre’s political judgment.
Mr. d’Entremont was clear that he did not feel alignment with the leadership of the party and with the negativity that Mr. Poilievre has come to be known for. If there are more floor-crossings to follow, this would put Poilievre in vulnerable position as he heads into a leadership review in January. But even if Mr. d’Entremont is the only one, his departure suggests that Poilievre struggles to keep moderates inside the party fold.
The relationship between a political party and its caucus members is based on trade-offs: MPs are expected to be team players, but they need to receive tangible benefits in exchange for that devotion and feel that, overall, any sacrifice of autonomy is worth the reward.
Chris d’Entremont clearly felt that this was no longer the case and he’s found a new political home. It is up to Pierre Poilievre to ensure that no one else in his caucus draws that conclusion.
Policy Contributing Writer Lori Turnbull is a Senior Advisor at the Institute on Governance.
