If they were to proceed with bankruptcy, they would need fees of £510 each for the court. There are forms which need to be filled in and which can be done online and saved as you go along. You either make an appointment at the court, or just turn up, depending upon what the procedure is at your local court. The judge looks at the forms and will then stamp them and you effectively become debt free.
You will then have an interview with the Official Receiver who will look at the circumstances surrounding your debts. If you have disposable income of less than £100 per month once priority bills have been paid, you will not have to pay anything towards the bankruptcy, if it is over that then you will pay between 50 and 70% of the excess for three years.
As regards the house, if it is in negative equity, it is not worth the OR selling is as there will be no profit for them. Someone, a friend or family member can buy back the beneficial interest for the sum I mentioned which means that the house is safe.
Take a look at this site:
It will explain more about it, and the forms are there to fill in as well.
Also visit the link I posted previously and give one or two companies on there a ring.