David Cameron refused to rule it out.
Theresa May was once passionate about the idea (while home secretary - she cooled on the idea once prime minister).
Boris Johnson claimed all options were on the table to make a success of his Rwanda deal.
And Liz Truss boasted she was prepared to do it too.
It's an idea which has long been popular with hawkish Tory backbenchers and, indeed, former cabinet ministers (like Suella Braverman). But now, amid rising public concern about illegal migration and anger about the courts' frustrating government deportation efforts, the appetite for withdrawal has gone mainstream.
Even Labour are trying to change the way the ECHR is implemented in UK law to reduce the number of blocked deportations.
Now, ahead of the Conservative Party conference in Manchester - in one of the least surprising announcements of the year - Kemi Badenoch has definitively committed to leaving the ECHR (if the Tories win the next election).
Mrs Badenoch is trying to stand strong. But there's a risk it looks like she's playing catch-up.
Reform promised to leave the ECHR as part of their election manifesto and Nigel Farage has continued to bang the withdrawal drum as his party has swept ahead in the polls.
Mrs Badenoch's leadership rival, Robert Jenrick, also made leaving the ECHR central to his pitch for the top job last year.
At the time, she argued the idea would be no silver bullet and refused to commit to the policy, though she didn't rule it out.
She's been on a cautious and circuitous route to acceptance, commissioning the shadow attorney general Lord Wolfson to carry out a review on the legal implications of staying or leaving across a number of policy areas, from deportations to prioritising British citizens for social housing.
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Three months and a 200-page report later, Lord Wolfson concluded that membership "places significant constraints" on the government's powers.
Mrs Badenoch argues that this process shows that "unlike other parties" - ie Reform - "we have done the serious work to develop a plan to do so".
Chris Philp, the shadow home secretary, claims his party have "thought about it properly" rather than announcing "slogans written on the back of a fag packet in a pub".
The key question
Reform has hit back with the evergreen question - why didn't they do this during 14 years of government?
Ultimately, Mrs Badenoch's predecessors all baulked at the idea of leaving a treaty championed by Winston Churchill, which forms the cornerstone of the post-war commitment to human rights across Europe.
Russia is the only other country to have ever left, after the invasion of Ukraine.
In practical terms, the policy creates a diplomatic minefield given the ECHR underpins both the Good Friday Agreement and the Brexit deal.
But with Reform threatening to send the party to electoral oblivion, the Tories are under pressure like perhaps never before. Their leader clearly feels she has no choice.
(c) Sky News 2025: ECHR move shows Tories are under pressure like never before