"Leaving with ‘no deal’ doesn’t remove any previous/current obligations/bills - unless of course the process is akin to bankruptcy."
I don't know if there is truth in this but if our political representatives do attempt to leave without paying the bill I can't imagine it will go well when it comes time to make a trade deal.
Unless we haves something the EU need (unlikely) then unpaid debt isn't going to make it easy to get a favourable trade deal.