I know that one of the basic premises of a limited company is that should a
company go bust owing a significant sum, in most cases the company owner
will not be personally liable for its debts.

However, what is to stop a company with debts but also assets, starting up a
new company with a new registration, doing the same business but simply
transferring all of the assets to the new company, leaving the old company
with just the debts and closing it down?