His critics say he's lazy, eats too much, sleeps on the job and would rather spend time with a "female acquaintance" than carry out his official duties.
The civil servant in question is no expenses-fiddling MP, but a four-year-old rescue cat named Larry.
Downing Street was forced to defend its feline resident after rumors of mouse sightings at the prime minister's official dinners.
Larry was nowhere to be seen when a mouse appeared at a recent dinner between David Cameron and his cabinet ministers, Agence France Presse said, leaving the PM to throw a fork at the intruder.
Chief mouse-catcher Larry has been neglecting his hunting duties in favor of sleeping or hanging out with a furry female neighbor, according to unnamed aides cited by the Daily Mail.
The slurs prompted speculation that Larry might be relieved of his duties - a possibility which a Downing Street spokesperson ruled out Monday, saying:
"Larry brings a lot of pleasure to a lot of people."