He had lately been living at the Battersea Dogs and Cats Home after having been taken in as a stray. He was recruited on Tuesday specifically for catching rats, but Prime Minister David Cameron's young children are believed to have been in favor of seeing him move in. Larry will be looked after by Downing Street staff, who helped choose him, and will have the run of most of the offices and official rooms as well as the garden.

Battersea said Larry showed all the signs of the hunter instinct needed for seeing off rats as well as the right qualities in coping with the demands of daily life at No. 10. "Larry may have had it tough as a stray but he's active, lively and confident," it said. "He's quite independent and has bags of character. "I can definitely see Larry holding his own at Downing Street."