Boris Johnson's brother quits as his minister and MP

British Prime Minister Boris Johnson on Thursday suffered yet another Brexit blow, this time closer to home, as his younger brother Jo Johnson quit as a minister in his Cabinet and also resigned as a parliamentarian of the Conservative Party.

In a move reflective of just how deeply divided the UK remains over its membership of the European Union (EU), the business minister and member of parliament from Orpington said that he had been forced to take the step after being torn between family loyalty and national interest.

The anti-Brexiteer, who is seen as an India-friendly politician in the UK having also lived there in his previous role as a journalist for ‘The Financial Times’, said he felt the tensions were “unresolvable”.

“In recent weeks I've been torn between family loyalty and the national interest - it's an unresolvable tension & time for others to take on my roles as MP & Minister,” he said in a Twitter statement, which concluded with “over and out”.

“It's been an honour to represent Orpington for 9 years & to serve as a minister under three PMs,” he said.

Jo Johnson voted Remain in the 2016 Brexit referendum, in contrast to his brother who co-led the Leave campaign. He resigned as a minister last year in protest at Theresa May's Brexit deal. But he re-entered government recently, after Conservative Party members elected his brother as leader in July.

Jo Johnson was seen as a popular Tory parliamentarian, who at the last general election won the Orpington seat by a 19,453 majority.

He is believed to have not given his party colleagues any heads up on his decision to resign, which came at the end of a tumultuous 48 hours for Boris Johnson after repeated defeats in the House of Commons.

His decision also marks the first Cabinet exit for the embattled British prime minister, who has now lost 23 members of parliament to either resignation or expulsion for siding with the Opposition.