He has faithfully served four prime ministers. He has the run of 10 Downing Street: "His access is really unlimited," says a close acquaintance.
And his productivity is superb. He was called in seven years ago on special assignment, which he carried out with a throughness MI6 or the CIA would admire. His mission: rid the ministerial residence of mice.
He is Wilberforce the cat, a white tabby who patrols everything at No. 10 from the basement kitchens to Prime Minister Margaret Thatcher's study with a sharp eye for intruders.
"Eitehr we had a cat or the mice would take over," says Downing Street office manager Peter Taylor, whose rooms Wilberforce calls home. So Mr. Taylor's mother collecter the eight-week-old kitten from the Royal Society for the Prevention of Cruelty to Animals in nearby Hounslow, filled in the proper forms ("Because the RSPCA needs to know that the thing's gone to a good home," says Mr. Taylor), and brought him back to one of the world's best-known residences.
Casting about for a name, his new owners found one nearby. "We have a statue here of a chap named Wilberforce with a silly-looking grin on his face," says Mr. Taylor. William Wilberforce was instrumental in abolishing slavery in the early 19th century. He would no doubt have been pleased to lend his name to a cat who is nobody's slave and disdains the servants' entrance.
He goes out, in fact, through the main hall, where his friends on the security staff click open the imposing black door with the brass "10" on it.
The tourists outside, gathered for a glimpse of the famous, bring up their cameras. Out walks Wilberforce.