The Foreign Office's new feline resident is settling into his home on Whitehall - and has already attracted a large online following on his official Twitter account.
The black and white cat, named Palmerston, was recruited from Battersea Dogs and Cats Home to join the Government department as "chief mouser", scaring off any unwanted pests.
Palmerston was immediately thrown into the spotlight on arrival at the Foreign Office - as he was greeted by a media pack.
"Wasn't expecting to give media interviews on my 1st day!", a post on his official Twitter account (@DiploMog) read.
The cat, who is apparently named after Viscount Palmerston, who was foreign secretary almost 200 years ago and twice served as prime minister, is also shown in a photograph posted on the account playing with a piece of brown string.
A post alongside the image reads: "Making myself at home @foreignoffice HQ."
The Foreign Office's newest member of staff may only have been on Twitter a few hours, but has already attracted more than 700 followers keen to see behind the scenes of the department.
Palmerston will be in good company in Whitehall, living just yards away from Larry, Prime Minister David Cameron's cat in Downing Street.
His upkeep will be paid for by a "staff kitty" and will assist pest controllers in controlling mice numbers at the King Charles Street building in London, the Foreign Office said.