Well they should approach their own bank as a start BUT the market is so slow at the moment, that banks are really shy of offering Bridging on a new purchase unless the borrower has signed contracts on their own in place.
They really need to sell their own before trying to buy anywhere else. I have a number of situations like this and some of my clients are coming around to the idea that they just cannot look at any property to buy until/unless they sell their own. There is a realisation that the market has changed dramatically from the heady, blithe, confident days up to mid 2006. Its now very cautious and very laboured.
mf