Jo Johnson, the brother of British Prime Minister Boris Johnson, resigned abruptly Thursday, citing “unresolvable tension” between family loyalty and the “national interest” as political turmoil surrounds Britain’s attempt to leave the European Union.

“It’s been an honour to represent Orpington for 9 years & to serve as a minister under three PMs,” Jo Johnson wrote on Twitter. “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. #overandout”

Johnson – a member of Britain’s Conservative Party, known informally as the Tories – served as a member of Parliament for Orpington and was a member of his brother’s Cabinet.

His abrupt resignation is just the latest bit of bad news for his brother, who has promised to deliver Brexit.

As The Washington Post reported Wednesday, Johnson, after just six weeks on the job as prime minister, has lost his governing majority, exiled some of his party’s most honored members and been slapped down by lawmakers three times in 24 hours.