Tell 'em to get stuffed... "unfair contract terms" comes to mind. A clause preventing you working for competitors of their clients may be reasonable, as you will have acquired sensitive knowledge, but anything else is just unnecessarily restrictive. For them to sue you, they will have to prove "damages", i.e. they will have to demonstrate how your action has caused them financial loss. This will be difficult, no?However, they may have got their clients to sign a similar agreement, which would have a lot more force because a) it's a B2B contract, and b) it seems reasonable to put protection in place to stop clients poaching their staff. So, you may find that their clients won't make you an offer anyway, if that's what you're hoping for in due course.Also, pls can you name and shame said employer?