Robert Jenrick has resigned as immigration minister over the government's plans for Rwanda, the home secretary said.
Mr Jenrick was absent from the frontbench as Home Secretary James Cleverley made a statement to the Commons on the Government's attempt to salvage a deal to airlift migrants who entered the UK illegally to Rwanda.
Friends of Mr Jenrick have told Sky News he has resigned.
When asked by LBC if Mr Jenrick has resigned, Home Office minister Laura Farris said: "I understand that he has."
His departure comes after emergency legislation aimed at reviving the stalled Rwanda asylum policy avoided the most hard-line option to leave the European Convention on Human Rights (ECHR).
This is something many on the right of the Tory party have called for, including former home secretary Suella Braverman.
Earlier she warned the Tories face "electoral oblivion in a matter of months" if the legislation introduced is "destined to fail".
Mr Jenrick is said to have pushed Mr Sunak for the toughest version of the legislation. But complying with those demands would have left Mr Sunak facing an outcry from his MPs from the more centrist One Nation faction.
Mr Sunak promised the emergency legislation after the Supreme Court ruled the plan to deport asylum seekers to Rwanda was unlawful. The draft bill, published on Wednesday, compels judges to treat the East African nation as a safe country and gives ministers powers to disregard sections of the Human Rights Act.