I don't think so. Say I am a cleaner. I work for cleaners r us. Three of my clients approach me and ask for direct cleaning. I say yes. Over three years I earn 15k from these three clients. Cleaners r us lose out on their commission, say 10k. They take me to court.
I don't think that would qualify as fraud by misrepresentation unless you approached the clients and they believed you were still working through the agency and therefore still have insurance or something... it's just fraud, otherwise.
There was a case near me late last year of a local woman who used details of men who had used a sex text service to contact the men. I can't remember if she ever worked for the text line or if she knew someone who did... anyway, she blackmailed one of the guys to get money, and for another couple, she sold them the usual pie-in-the-sky stories that are always in magazines with foreign waiters and the likes. Pocketed £42k, which she said was used to pay her bills. She was found guilty and people seemed pretty evenly split over whether she deserved to go to jail or not... the headlines were all around "Local woman turns to sex crime to pay rocketing bills" etc... at the trial, her bills weren't just rent and electricity, but holiday payments, clothes, Sky, take-aways. Bills from her POV, luxuries to others! I don't remember seeing what she was sentenced to in the end, but there's a lot to be said for the details of an individual case...
Without knowing what she did, what remorse has been shown and how much damage it did, it's hard to find a suitable treatment. One guy lost £15k. Were the others £500 each or £13k each? What happened to the money?
I hate the idea of anyone going to prison, but it's tough to judge what a suitable punishment is. Most places don't give custodial sentences out lightly, as prisons are so oversubscribed, although it does happen.