It is possible in certain case to set up a limited liability partnership, but I can't remember the tax consequnces - from memory they are the same as for an ordinary partnership.
It's not so much the mortgae you need to worry about (which is after all a debt), but you shoudl look at transferring the assets - ie the house, any savings accounts, shares etc, if there is a risk. Get yourself a decent accountant as you prpbably will also want to look fairly carefully at what expenses are best (ie most tax-efficiently) borne by the partnership rather than by you as a family.