I recently went through a mortgage broker to negotiate a new mortgage as my current lender is not delivering at the end of the honeymoon period. I got an in principle offer based upon my income and current debt commitments. When actually applying for the mortgage they decided that they no longer wanted to lend me the money (purely because of my credit score and income - which they were happy with at the "in principle stage" and nothing has changed. They sent me a letter to say that as "I" had withdrawn from the mortgage and they would charge me £150.
I suspect that this will be settled in the small claims court. Their behaviour is totally unacceptable... Barclays should have let them go under.