British Chick Lit where man hires a woman to pose as girlfriend

I'm trying to find this British chick lit book that is set in modern day. The main character works for a fashion magazine and is struggling to survive--the only apartment she can afford is so humid she has to keep all her stuff in ziploc bags. She meets a man who hires her to act as his girlfriend mostly for business related events and meetings. She also is a prolific and talented knitter. Anyone know what it's called?