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.
"I don't know whether they're pleased or disappointed," chuckles Mr. Taylor, adding that he is a "well-photographer cat."
Yet despite his distinct lack of pedigree, he apparently mingles freely with world leaders. "He passes them on the stairs," says his master. "They're all the same to him -- they're just people."
Perhaps it is this easy-going nature that accounts for his seven-year tenure at No. 10 -- tenure which recent British prime ministers may well envy. Has he, over the years, come to resemble the leaders he has served?
"He was a very scared cat when he came here," recalls Mr. Taylor. "He's still a bit shy if someone makes a quick move," he notes, adding that strangers (of whichever political party, apparently) "should be wary of him because he's got some very sharp claws and he's rather quick to react."
Wilberforce regularly steps across the street to the foreign office, visits the chancellor of the exchequer next door at No. 11, and strolls across the horse guards parade to the Scottish Office. One place he rarely visits, however , is the Cabinet room -- although former Prime Minister Harold Wilson, who was extremely fond of him, took him in for a look once.
So it came as a surprise to find him on a later occasion showing keen interest in the room. For three days "he couldn't stay away," says Mr. Taylor. Wilberforce, it seems, knew very well what was going on in there: the Icelandic fish talks.
"I should think the Icelandic prime minister would remember him," says Mr. Taylor.