A SENIOR law officer for the UK Government has resigned over the UK Internal Markets Bill fiasco.

Lord Keen is understood to have offered his resignation to the Prime Minister this afternoon.

It comes after he told The House of Lords that the trade bill does not "constitute a breach of international law or of the rule of law”.

However Northern Ireland secretary Brandon Lewis had earlier told MPs it would break international law in a "specific and limited" way.

Lord Keen of Elie QC, the Advocate General for Scotland and a justice minister, was further humiliated this morning when Mr Lewis said his colleague was wrong to dispute the government's stance. 

Alistair Carmichael also raised the blunder with Prime Minister this afternoon, and said the Government was Last week the Secretary of State for Northern Ireland said that the UK Internal Market Bill would breach our obligations under international law.

"Yesterday the Advocate General for Scotland said that the Secretary of State was wrong to say that. Today the Secretary of State says that the Advocate General was wrong to say that he was wrong.

“It’s of course possible that they are both right in saying that the other is wrong." 

Labour said the Lord's reputation was "shot" after the MPs remarks, with rumours emerging he was set to resign last night.

He is now understood to have offered his resignation to Boris Johnson.

Downing Street has not confirmed yet if the resignation has been accepted, as it is believed there has been an attempt to persuade him to stay. 

Labour Peer Lord Falconer accused Lord Keen of misleading the House of Lords, and said his position was "untenable" shortly before he offered his resignation. 

He said: "Both the government and now Brandon Lewis specifically are rubbishing what Lord Keen said on the law, making his position absolutely untenable. 

"He cannot with any degree of personal honour or professional duty continue to advise the government on the law.

"Lord Keen has misled the House of Lords in two respects. Firstly saying Brandon Lewis answered the wrong question when Brandon Lewis himself said he hasn't.

"Secondly giving his views as if they represented the legal position of the government when he knew that was not the case." 

Labour peer Lord Foulkes said Lord Keen had done the right thing by offering his resignation.

"I am pleased to see that Lord Keen has done the honourable thing and resigned, particularly following our exchange yesterday in the Chamber over the Government's breach of the law" he said. 

SNP MP and QC Joanna Cherry said the UK Government would have a difficult time replacing him.

She tweeted: " I imagine the UK Government will find it hard to find any member of the Scottish Bar @FacultyScot  to replace Lord Keen as Advocate General for as long as the Tories are intent on breaking international law."