The First C Lord of the Treasury - or Sybil, Alistair Darling's cat as she was more popularly known - has died after a short illness, the Chancellor's office has reported.

Sybil, a black and white moggy named after Basil Fawlty's wife in the 1970s sit-com Fawlty Towers, passed away at the London home of friends of the Chancellor. Although her basket was a feature of the 11 Downing Street state rooms the Scottish-born cat had only ever been a short-term resident at the famous address.She moved into the Chancellor's flat from the Darling family home in Edinburgh in 2007 but left six months later after failing to settle.

At the time the Prime Minister's official spokesman was forced to scorch rumours that the next door neighbours, the Browns at Number 10, disliked the cat.

Sybil's predecessor, Humphrey the cat, wandered around Downing Street for years after first arriving as a stray in 1989.

Named after Sir Humphrey from the Yes Minister television series, the cat survived the Thatcher and Major eras but moved out just six months after Tony Blair became prime minister in 1997.

There were official denials that the cat had been forced out on the orders of Cherie Blair and photos of Humphrey in his retirement home had to be produced in order to prove his wellbeing. He died in 2006.

All jokes about the economy undergoing a "dead cat bounce" were banned in Whitehall yesterday as a mark of respect for Sybil.

A spokesperson said there had been a short "paws" for reflection and then the Treasury got on with saving the economy.