[MovedGoalPosts]

If any transfer of even a part ownership of property is going to have legal standing then it will need registering against the title. Whoever did the conveyancing for that should swiftly find the mortgage charge against the property which would prevent a transfer of any title until the mortgage agreed. Clearly they are not going to agree unless the debts are settled and a new mortgage allowed with the new owners, something that seems rather unlikely to happen.

Bottom line here whatever hair brained scheme he might be considering, wouldn't stand real scrutiny, and unless he is prepared to sit down with leagl advisors, yourselfs and the mortgage company to come to some binding agreement this is going to go round and round in circles until the inevitable repossesion of the property.