<P> For the first series, episodes were written by Mack and Andrew Collins, with members of the cast credited for additional material . Because the eight episodes of the second season had to be written and filmed in a short space of time, Avalon Television brought in Nick Stacey, Paul Kerensa and Simon Evans to join the writing team . Mack, Collins and Stacey concentrated on writing the main body of the episodes whilst Kerensa and Evans were involved in storylining, rewriting and' gagging up' the episodes . The third series saw the writing team expanded, with Darin Henry, Daniel Peak and Simon Dean contributing to the main episodes (all co-written with Mack); the "gag writing" team was also expanded, from two members to as many as eight, not counting the main writers, on a single episode with Milton Jones amongst the additional writers of the show . </P> <P> In the original pilot of the series, which has not been aired, the part of Kate was played by Catherine Tate . However, due to the success of The Catherine Tate Show, her character was re-written for the American actress Megan Dodds . </P> <P> The theme song is performed by Frank Sinatra impersonator Stephen Triffitt . </P> <P> The flat in which Lee and Kate / Lucy lived from 2006 to 2015 is No 17 . In a DVD commentary for the first series, it was mentioned that "Number 17" was originally considered as a title for the series, before the name "Not Going Out" was decided on . </P>

Who sings the theme song to not going out