Simon Pegg is to star in a David Schwimmer-directed romantic comedy about the London Marathon. The film, entitled Run, Fatboy, Run, also stars Thandie Newton, Hank Azaria and Dylan Moran. It is currently filming in London for a 2007 cinema release.

Run, Fatboy, Run centres around an overweight man who leaves his fiancée on their wedding day, only to realise years later that she's the woman of his dreams. Unfortunately for him, she's just about to marry a rich and handsome man so, in an attempt to win her back, he decides to run the London Marathon.

Pegg and Schwimmer previously worked together on Britflick, Big Nothing, which received a limited cinema release earlier this month.