Kate is the star of the edgy new campaign which uses the cheeky catch cry 'Let Them Eat Kate'
Kate's relationship with label owner's, Vivienne Westwood's son Joe Corre, 40, and his estranged wife Serena Rees, 39, was compromised earlier this year when Serena ran off with Paul Simonon, former bassist of rock band The Clash - and the husband of one of Kate's best friends.
Fashion sources said it was the underlying reason why Kate's contract was not been renewed.
Lily Allen was hired to take over from Kate, but she was ditched after Joe and Serena failed to agree if she was the right girl for the job.
According to a source, Ms Rees chose Lily but Mr Corre "wasn't keen".