Grant Shapps, a former transport minister has been appointed as her replacement.
British interior minister Suella Braverman has resigned from office after sending an official document from her personal email.
This is considered a "technical infringement" of government rules.
Grant Shapps, a former transport minister has been appointed as her replacement.
“I have made a mistake, I accept responsibility; I resign," she said in a letter to Prime Minister Liz Truss posted on Twitter.
Braverman also took a swipe at Liz Truss’ government, saying she had "serious concerns about the direction of this government”.
Not only have we broken key pledges that were promised to our voters, but I have had serious concerns about this Government’s commitment to honouring manifesto commitments, such as reducing overall migration numbers and stopping illegal migration, particularly the dangerous small boats crossings,” she added.
Truss has faced opposition from her own Conservative Party over her botched economic plan.
During a session of Prime Minister's Questions on Wednesday, Truss apologised to Parliament and admitted she had made mistakes during her short tenure as the UK's head of government.
But while she was talking, some lawmakers urged her to resign.
But she insisted that she is “a fighter and not a quitter”.
“I have acted in the national interest to make sure that we have economic stability,” she said.