The resignation of David Davis came two days after the UK cabinet supported Prime Minister Theresa May's plan for a "soft" Brexit. "The best person to do this would be somebody who believes in it, not me," Davis told BBC radio.
LONDON — UK Brexit Secretary David Davis resigned from Theresa May's government on Sunday night, in protest against the prime minister's approach to negotiations with the EU and shift towards a softer Brexit.
Davis, who has been leading negotiations for the UK, said in a letter to May that "the current trend of policy and tactics" meant it was "look less and less likely" that the UK would leave the single market and customs union.
He added that he was "unpersuaded" that May's handling of talks, particularly her recent shift to a soft Brexit, "will not just lead to further demands for concessions" from EU negotiators in Brussels.
"The general direction of policy will leave us in at best a weak negotiating position, and possibly an inescapable one," Davis told May in a resignation letter.
Speaking to the BBC's Today programme on Monday morning, Davis said the plan was not a "plausible thing" and added: "The best person to do this would be somebody who believes in it, not me."
He hinted that his departure would be a warning to May not to make any more concessions to Brussels.
"My fear is they'll take what we've offered already and demand some more... We are giving too much away, too easily," he said.
"It [the resignation] might put a little pressure on the government to not make more concessions."
The pro-Brexit MP was followed out of the door by ministers Steve Baker, who will also quit the out of the Department for Exiting the EU. Suella Braverman, another DExU minister, has not resigned, despite reports suggesting she had.
May is set to announce Davis' successor on Monday morning.
In a letter responding to Davis, the prime minister said she was "sorry" about his departure but added that she did not agree with his characterisation of the state of Brexit talks.
"I do not agree with your characterisation of the policy we agreed at cabinet on Friday," she said.
Davis dramatic late-night resignation came just days after he along with the rest of May's Cabinet agreed to support the prime minister's plan for a softer Brexit at a meeting of ministers in Buckinghamshire.
Under May's proposal, the UK would stay wedded to the EU standards for the trade and goods and collect EU tariffs on the bloc's behalf, in order to preserve frictionless trade and the open Irish border.
However, it would make new free trade deals with certain countries, like the USA, much less likely, and would leave the UK under some influence of the European Court of Justice. An eight-page critique of the plan, circulated by pro-Brexit Conservative MPs, described it as the "worst of all words."
"The Cabinet decision on Friday crystallised the problem," Davis said about the plan in his letter to May, calling himself a "reluctant conscript" if he had stayed in the role to push May's plans.
Labour leader Jeremy Corbyn said Davis' resignation proved the Conservative government was "incapable of delivering Brexit" while Labour Party Chairman, Ian Lavery, said May "has no authority left."