Rishi Sunak suffered a rebellion on his flagship anti-smoking bill last night, with 57 Tory MPs voting against it. It was a free vote, so the rebellion was not - on paper - an active choice to undermine Sunak's authority.
But not only did it highlight the significant rifts present in the parliamentary party, it also drew attention to some key leadership hopefuls operating behind the scenes.
The list of those voting against the bill was not short of big names. Business Secretary Kemi Badenoch, former immigration minister Robert Jenrick, former PM Liz Truss and ex-home secretary Suella Braverman all made the list.
Meanwhile, Commons Leader Penny Mordaunt and former home secretary Priti Patel both abstained.
Rishi Sunak suffered a rebellion on his flagship anti-smoking bill last night, with 57 Tory MPs voting against it. It was a free vote, so the rebellion was not - on paper - an active choice to undermine Sunak's authority
PA
Mordaunt's team said she abstained deliberately because she sees the bill to be unworkable.
Badenoch, who has long denied wanting to steal Rishi Sunak's job, told LBC Radio she thought long and hard over her decision given her father died of cancer. But she came to the conclusion: "I don’t think the end justifies the means."
What makes these leadership hopefuls' decisions to vote against the legislation so telling, is that - unfortunately for Sunak - last night's vote was about so much more than just smoking.
Many MPs within the party see it as a fundamental issue of conservatism.
Smoking rebel-in-chief Truss claimed the plans are evidence of the "nanny state" in action and dubbed them "profoundly unconservative".
While former PM Boris Johnson said the legislation is "absolutely, absolutely nuts".
Speaking at a conservative conference in Ottawa, the former prime minister hit out at some of the policies "being done in the name of conservatism".
He told delegates: "I see my beloved party... we’re banning cigars. And what is the point? The party of Winston Churchill wants a ban. I mean, donnez-moi un break as they say in Quebec. It’s just mad."
Sunak, who is still battling devastating approval ratings, is clinging on in an attempt to lead the party to the polls at some point this year. But in the background, many MPs on the right of the party are not-so-quietly expressing concern that their Tory leader isn't a true Tory at all.
And Badenoch's justification for her decision to vote against only serves to highlight it. In her decision to vote against the bill, she declared that, despite her personal experiences, she is willing to put true conservatism above all else.
While it seems unlikely (but not impossible) that Sunak will be ousted before a general election, last night was a perfect opportunity for future leadership contenders to show that, unlike Sunak, they can be true defenders of conservatism. No doubt they will all be waiting in the wings when there is a vacancy at the top of the Tory party.