The character of Keith Barret was first performed by Rob Brydon on stage and then on Radio Wales. The central conceit of Keith's character was that he had been cuckolded by his wife and was living in blissful ignorance of the fact. Brydon's early performances showed Keith to be an exaggerated, cartoon-like individual with a high voice and not the tormented soul that he eventual became.

After appearing in the successful film Lock, Stock and Two Smoking Barrels, Brydon decided to cash in on the small amount of fame this afforded him by making an audition tape featuring several of his creations. It was at this point that he, by chance, bumped into former classmate Hugo Blick who had successfully directed Operation Good Guys. Blick was looking to work on a quieter, less raucous project and felt that Keith had great potential.

The first series of Marion and Geoff followed and was rapturously received. The sixth episode of the series featured Keith describing, in detail, the day that his marriage finally collapsed at a summer barbecue and it is this event that is shown in A Small Summer Party.

The special was, on the whole, greeted with a warm reception but the writers drew some criticism for the inconsistencies between Barret's description of events and how they played out. They defended themselves however, by explaining that Keith's account was simply his memory of the day and that he was an unreliable witness.

The character continued to prove popular and a second series of Marion and Geoff followed with the DVD of this series containing the director's cut of A Small Summer Party. Brydon then toured as the character and made two series of The Keith Barret Show in which Keith would quiz celebrities about their successful relationships.