After graduating from Churchill College, Cambridge as a mature student and then working as a sub-editor for magazines, Blackwell started writing TV comedy in 1999 on shows such as Have I Got News For You, The Kumars at No. 42, Alastair McGowan's Big Impression and The Armstrong and Miller Show, for which he created the duo's street-talking RAF pilot characters. He first worked with Armando Iannucci in 2003 on the topical Channel 4 show Gash. He went on to write on all four series of Iannucci's political sitcom The Thick of It and co-wrote its spin-off film In The Loop, which was nominated for an Oscar for Best Adapted Screenplay.
