Sorry I'll clarify it - if it's a case that the debtor is just trying to walk away, it's unlikely that they will be made bankrupt, just for the sake of discharging the negative equity. If the debtor can make the repayments, then they should continue to do so, that would be the view of any court. These measures are not a generalised debt write-off system, they are designed for people in financial difficulty.
But, where the borrower's mortgage is unsustainable, and they can't meet the repayment, negative equity can be brought into the mix in the PIA - it's a negotiation, and as has been stated on here previously, and as we know write-offs in settlement are happening already. But these are normally where the debtor gets the best price and settles in final, and the bank takes a hit for the money.
The banks do not want a raft of property on their books. If restructuring a mortgage until the borrower is 100 years old isn't going to be workable in reducing the payments to an affordable amount, then the bank can either
a) let the borrower declare themselves bankrupt, and official receiver recovers the value of the asset
b) seek repossession, as they have security over the asset, they sell it themselves, and the borrower declares bankruptcy on the balance of negative equity
c) restructure the mortgage so that the borrower can afford the repayment, and if this requires debt write-off to enable this it could result in a better deal for both the bank and borrower.
There is nothing I can see in this bill precluding negative equity negotiation - where the mortgage as it stands is unsustainable - (it doesn't have to be for the full value of the negative equity - as long as the mortgage balance reduces, it could be workable), and if it works for the lender and the borrower, why not!