There won't be one in the box, put it that way. Unless the retailer, or whoever you bought the set off, agreed to give you one, you probably won't be getting one when the set arrives.
You can pick up good cables for about £30. Probably best to avoid the ones on offer in Curry's. They always seem pretty expensive (about £60 for a Belkin). According to What HIFI, QED do some pretty good HDMI cables. I picked up one of these for £30 online, a Qunex I think it was called.