Former UK Home Secretary Suella Braverman accused Rishi Sunak of betraying the public and breaking his promise to clamp down on immigration, in an explosive letter that threatens to exacerbate the febrile mood on the right of the governing Conservative Party.

Referring to a “deal” that Braverman said Sunak agreed with her in exchange for supporting his bid to be Tory leader, she said Sunak had committed to reduce overall legal migration and exclude the European Convention on Human Rights from the government’s policy toward asylum seekers.

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“You have manifestly and repeatedly failed to deliver,” she said. “Either your distinctive style of government means you are incapable of doing so. Or, as I surely must conclude now, you never had any intention of keeping your promises.”

She continued: “Your rejection of this path was not merely a betrayal of our agreement, but a betrayal of your promise to the nation that you would do ‘whatever it takes’ to stop the boats.”

Braverman concluded that Sunak’s premiership had been “uncertain, weak, and lacking in the qualities of leadership that this country needs.”

Sunak’s office did not immediately respond to a request for comment.