Lord Keen of Elie, Scotland’s attorney general, reportedly resigned earlier on Wednesday.
The prime minister appeared to suggest he was trying to convince the peer to stay in his post, telling a committee this afternoon that “conversations on this issue are continuing”.
But Downing Street has now confirmed that Lord Keen has resigned, with a spokesperson adding: “The Prime Minister thanks him for his service. ”
It follows the admission of the government which proposed Brexi legislation would violate international law.
Britain’s Home Market Bill, which passed its first parliamentary hurdle to become law earlier this week, has come under heavy criticism in Westminster and Brussels.
The EU has threatened legal action and said it could threaten ongoing trade negotiations over a future EU-UK relationship.
Shortly after Lord Keen’s resignation, Mr Johnson partially descended on his controversial bill – and vowed to give disgruntled backbench MPs another vote before any of the powers are used.
However, that is on condition that they pass the home market bill when it is due to complete its trip to the Commons early next week.
Sky deputy political editor Sam Coates said Lord Keen “was one of the government’s lawyers – he was responsible for carrying out legal duties”, adding: law. ”
Coates explained: “He tendered his resignation earlier and meanwhile it appears ministers were trying to talk him out of leaving government – but conveniently, after the PM finished before the Members’ Liaison Committee, Downing Street announced that he was missing.
“It appears that Downing Street and the government are keen to know that their plans will continue to violate international law and that was something this lawyer could not continue to tolerate. This puts additional pressure on other legal scholars, including Justice Secretary Robert Buckland and Attorney General Suella Braverman. ”
Last week, Northern Ireland Secretary Brandon Lewis said in the House of Commons that the bill, if passed, would reinterpret the Northern Ireland Protocol – a key part of the Withdrawal Agreement – and thus violate international law “in a very specific and limited way”.
However, in the House of Lords on Tuesday, Lord Keen told his peers that the bill “does not violate international law or the rule of law”.
He also claimed that Mr Lewis had “basically answered the wrong question” when asked about the bill in the Commons.
“I made sure of the correct legal position in this context,” said Lord Keen.
But on Wednesday morning Mr Lewis contradicted Lord Keen’s assertion and said his comments in the House of Commons last week were “absolutely in line” with the government’s legal opinions on the matter.
He said: “I gave a very direct response to Parliament last week, in accordance with the position of the Attorney General.
“My position is fully consistent with the legal advice the Attorney General has issued. “
Speaking to the House of Commons Northern Ireland Affairs Committee, Mr Lewis added: ‘I read something very specific because I wanted to make sure what I said … to make sure I gave a clear answer in the House. ”
On Wednesday in Brussels, the President of the European Commission, Ursula von der Leyen, took advantage of her annual State of the Union address to warn the United Kingdom not to be able to unilaterally cancel the withdrawal agreement.
“This Withdrawal Agreement took three years to negotiate and we have worked tirelessly on it line by line, word by word, and together we have succeeded,” she said.
“The European Union and the United Kingdom have agreed that this is the best and the only way to ensure peace on the island of Ireland and we will never return to this point.
“This agreement has been ratified by this House and by the House of Commons. It cannot be unilaterally changed, ignored, ignored.
“It’s a matter of law, trust and good faith. ”
Mrs von der Leyen said Margaret Thatcher had always insisted that the UK honored its treaty commitments.
She quoted the former British prime minister as saying: “Britain is not breaking treaties. It would be bad for Britain, bad for relations with the rest of the world, and bad for any future trade treaty. ”
Ms von der Leyen added: “It was true then and it is true today. Trust is the foundation of any strong partnership. ”
A senior official and the government’s most experienced lawyer had already resigned following the dispute in Westminster over the UK’s internal market bill.
Sir Jonathan Jones, permanent secretary in the government’s Legal Department, will step down before his five-year term ends next April.