The Streets frontman apparently jumped at the chance to work on the film as he is a big fan of the television series.
"Mike is the perfect fit," a source told The Sun. "All the material he is writing for the film is new. He is really excited about the whole thing."
The film sees the boys travel to Malia, Crete on a lads' holiday and is to be produced by Film4.
It is believed that the soundtrack will be available just before the movie's release on August 19.
Skinner recently admitted that his age was the reason he decided to retire from The Streets.