The government’s longest serving justice minister, Lord Keen of Elie (Richard Keen QC), has resigned in the latest twist to the row over whether proposed Brexit legislation would break international law. The Blackstone Chambers barrister said he had 'found it increasingly difficult to reconcile' his obligations as a lawyer with provisions in the Internal Market Bill.

Media reports this morning said that Lord Keen had offered to quit amid confusion following the Northern Ireland secretary's statement that clauses in the UK Internal Market Bill would break the law in a 'very specific and limited way'. Brandon Lewis was answering a question posed by Bob Neill, chair of the House of Commons justice commitee, last week.  

In evidence to the Lords EU committee yesterday, Lord Keen denied that the measure would contravene the law, saying that Lewis had 'answered the wrong question'. The bill's powers would be activated only after what the UK perceived to be a breach of good faith by the EU, he said.

However appearing before the Northern Ireland select committee this morning, Lewis said he had spoken to Lord Keen and 'he agrees the answer I gave was the correct answer… Now he’s aware of the actual specific question I was asked by my honourable friend last week he is in agreement with me that I was correct.'

The prime minister initially refused to accept the resignation, which came as concessions were offered in a bid to head off a Tory rebellion over the bill. However in his resignation letter Lord Keen said he had 'endeavoured to identify a respectable argument for the provisions [of the controversial clauses] but it is now clear that this will not meet your policy intentions'.

Lord Keen, who is jointly qualified in England and Scotland, was called to the bar in 1980. He was appointed advocate general for Scotland in 2015.  He became the spokesperson for Ministry of Justice business in the Lords in July 2016 and rose to prominence when he appeared for the government last year in the Supreme Court prorogation case. 

The shadow attorney general, Lord Falconer of Thoroton, said: 'This has been a week of chaos from the government’s own law officers...  and their authority is completely shot.'