As I understand it, English Heritage is the body responsible for the upkeep of any building that has listed status, and from an interested citizen point of view, a serious case of neglect has occured. The owners have been shoddy at best and probably inept in the upkeep of a historical building.
As to the above, I would add that the building falls under the " National Heritage Act 1983 " and thus has legal protection. Within Civil Law, a claim may be submitted for neglect however this will carry significant costs, Barristers fees and research related to the case. Payable if losing the claim but also payable to the winning claim. You are looking at around 1 Million of relevent currency units. Law does not come cheap but I find it a grubby practice and have chosen not to engage,. I prefer the analytical aspect of Law, the theory if you like, it is about the logic and the variables of a case.
Nothing is clear cut , Especially if a Jury is involved.. Guilty as sin but aquitted by a jury? Go figure !