If he is closing the original company wouldn't that mean your being made redundant so he would have to pay you redundancy.
Correct.
Closing a company just to clear debts and setting up a new one is dodgy anyway.
As said, get some legal advice - 1st hour is usually free at a solicitors or speak to your uninon (you are in a union aren't you?). CAB are really busy atm so you might struggle to speak to someone their.