The show employs Ian Martin as a "swearing consultant"; one of his roles is to pen the complex and creative insults used in the show.
Each episode also has a credit for "the cast" under the writer credits. This is due to some of the dialogue being improvised.
In episode 2 of series 2 Hugh Abbot remarks that the prime minister's wife thinks he is "very probably a registered nonce". Chris Langham, the actor who plays Hugh, was arrested, tried, and convicted for possessing child pornography.
In series 4, Roger Allam's character speaks the line "He's Lewis, I'm Morse." A few years later, Allam played the superior to Inspector Morse in "Endeavor."
In series 2 episode 2 Hugh mentions to Robin that she is entering "the lair of the white worm" when she attendeds Malcolms 8.30am meetings. Peter Capaldi starred in the 1988 Ken Russell adaptation of lair of the white worm alongside Hugh Grant and Amanda Donohoe
The character of "Malcolm Tucker" is closely based on Tony Blair's press secretary, Alistair Campbell.
One of the main characters is called Glen Cullen. Glencullen is the name of two places in Ireland (a village in County Dublin and a townland in County Mayo).