Political careers are often short and brutally curtailed. To spend 10 years at the heart of the British government, working for three successive prime ministers, and still be loved by most colleagues, despite a reputation for grumpiness and being rudely territorial, is remarkable. Larry, who hits a decade in Downing Street on February 15, is the great survivor.

He has unseated Cabinet ministers, charmed and disrupted U.S. presidents, and even been stroked by my eight-year-old daughter. He has never given an interview, though he seldom hides his opinion. Officially, he holds the title of Chief Mouser; most of us in Westminster know him as just Larry the Cat.