It's a very difficult situation to be in. Being realistic you have to drop the house to a level at which it will sell as stated by previous posters even if this means it will not cover the mortgage/bridging loan. You have not hit this level yet. Also it seems both houses are in negative equity, it might be a good idea to sell both houses however unpalatable this may seem, take the hit, and rent for a while. Nobody knows if things will get worse or better. The bank cannot help you in these circumstances even if they lent irresponsibly. If your son had a regular mortgage on the property and rented it out would the rent cover the mortgage, this is the only other solution. What is the interest rate on the bridging finance?