Wilberforce, a black and white tomcat who was a companion to four British prime ministers after straying onto Downing Street in 1973, died in his sleep Thursday at the age of 15.
The feline, often seen lounging on the front doorstep of the prime minister's official residence at No. 10 Downing St., developed a reputation for being "the best mouser in Britain."
Wilberforce was found during the tenure of Prime Minister Edward Heath and served as a mouse catcher and pet for successive administrations.
"He received lots of mail, people wanting to know how he was, wish him luck," and the Downing Street staff answered for him, a staff spokesman said.
Prime Minister Margaret Thatcher talked to Wilberforce when she encountered him in the corridors of power, and she gave him a special farewell present when he retired to a private home at an undisclosed location in Essex, northeast of London, more than a year ago.
One of his last meals at Downing Street was a tasty can of the best Soviet pilchards--a kind of herring--picked out specially by Thatcher at a Moscow supermarket during a tour of the Soviet Union.
Wilberforce will be buried near his home, the office said.