Conservative MP George Eustice has resigned from the government over Theresa May’s promise to allow MPs a vote on delaying Brexit if her deal is rejected.
The farming minister said he would be voting for her deal when it comes back to Parliament next month.
But he feared the PM’s offer of votes on delaying Brexit could lead to the “final humiliation of our country”.
Mr Eustice is a longstanding Brexiteer, failed to get elected as a UKIP MEP before joining the Conservatives.
He is the 14th member of Theresa May’s government to resign over Brexit.
The MP for Camborne and Redruth in Cornwall said he was resigning with “tremendous sadness”.
He said in his resignation letter: “We cannot negotiate a successful Brexit unless we are prepared to walk through the door.”
The ex-farmer was a former press secretary to David Cameron – and played a leading role in Mr Cameron’s 2005 Conservative leadership campaign.
His resignation comes after Theresa May’s decision on Tuesday to allow MPs a vote on delaying the UK’s departure from the EU, or ruling out a no-deal Brexit, if they again reject the withdrawal deal she has negotiated with the European Union.