Boris Johnson’s Brexit plans have suffered another blow after the government’s law officer for Scotland quit in protest despite an eleventh hour climbdown by the prime minister.
No 10 announced that MPs would be given a new “lock” before controversial powers contained in the Internal Markets Bill can be used.
But the concession was not enough to convince Lord Keen, a member of the government’s frontbench in the House of Lords, to stay in his post.
Mr Johnson is facing a rebellion on his own benches after a cabinet minister said the bill, currently going through the Commons, does break international law “in a limited and specific way”.
Lord Keen of Elie had been the Advocate General for Scotland, the UK government's law officer for Scotland.
But his position was cast into doubt after he contradicted Brandon Lewis, the Northern Ireland secretary, to tell peers the controversial bill did not "constitute a breach of international law or of the rule of law".
He claimed that Mr Lewis had "answered the wrong question" in his comments to MPs.
But within hours Mr Lewis had reiterated his position, telling MPs that he had given “a very straight answer" last week.
In his resignation letter Lord Keen told the prime minister he had found it “increasingly difficult” to reconcile his obligations as a law officer with the prime minister’s policy intentions.
His resignation came despite Mr Johnson’s decision to bow to demands by backbenchers to give MPs another vote before the powers can be used.
Many Tory MPs had been expected to vote for a similar amendment, tabled by the Tory MP Sir Bob Neill, next week.
The deal was brokered between Mr Johnson, Sir Bob and Damian Green, the chair of the One Nation caucus of Tory MPs.
But it will not satisfy all those with concerns around the Bill, who fear the message it could send about Britain as a global power.
Nancy Pelosi, the speaker of the US House of Representatives, has already warned Congress will never pass a free trade agreement with the UK if legislation to override the Brexit divorce settlement was to "imperil" the Northern Ireland peace process.
However, Mike Pompeo, the US Secretary of State told a press conference that the US “trusted” Britain.
Robert Buckland, the justice secretary, has also suggested he could resign if the law was broken in a way he found “unacceptable”, while Tobias Ellwood, the Tory MP and chair of the Commons Defence committee has compared No 10’s strategy to “Nixonian madman theory”.
The legislation has also come under fire from all five living former prime ministers, including Mr Johnson’s immediate predecessors Theresa May and David Cameron, as well as Brexit-backing Tory grandees like former leader Michael Howard and ex-chancellor Norman Lamont.
Earlier this week the government suffered a blow as a Tory MP Rehman Chishti resigned as the prime minister's special envoy on Freedom of Religion or Belief in opposition to the clauses in the Bill.
In an attempt to quell the growing rebellion, Mr Johnson has accused the EU of underhand tactics and said the clauses are necessary to protect the status of Northern Ireland within the UK.
He told MPs this week the bill “should be welcomed by everyone who cares about the sovereignty and integrity of our United Kingdom”
Mr Johnson did admit he said he understood the concerns of those who felt unease over the measures, which he had no desire to use. They were an “insurance policy” which would never be invoked if there is a future trade deal with the EU, he said.