I found this reference on Google.
Private nuisance, as defined in Bamford v Turnley 1860, amounts to “any continuous activity or state of affairs causing a substantial and unreasonable interference with a [claimant's] land or his use or enjoyment of that land.”
So in this case the branches are a continuous state of affairs, but I can't see how they are a substantial or unreasonable interference with the use of the land.
It is so important to remember that nuisance, as used in the Tree Regs, is not in its common sense but in the legal sense, such as given in the abovementioned case. And the use of the exemption is only to the extent required to abate the nuisance, not to eliminate all encroachment.
And inevitably the word 'actionable' has to be examined. It carries with it the principle that the wrong must be creating actual and measurable damage or loss of enjoyment.
The Tree Regs don't say 'for the ... abatement of an actionable nuisance' they just say 'for the ... abatement of a nuisance'. But I think it was clear from Perrin that the nuisance has to be significant to the extent of being actionable. If it was truly Parliament's intention through the exemptions to make sure TPOs don't cause someone to be in a situation of being unable to abate a nuisance that otherwise would find him on the losing end of an action for nuisance, then that's entirely appropriate.
And that's what I'm going with for now.
Should Gary's client, rather than getting a deliberate TPO application knockback, serve 5 day notice on the Council of his intention to abate a nuisance? Well, I see an important point here, the Council that receives a 5 day notice and doesn't prevent the work is not condoning it. The 5 days may be provided only to allow the Council to visit and take evidence of the condition of the tree. The Council's failure to stop the work is not, in my current thinking. proof that the nuisance is actionable. How could it be since the Council may not be party whatsoever to the preceding exchanges between landowners and such evidence as there might be that there is measurable loss. They can't know if it's actionable, at least not quickly enough to stop the work. Do they even have the legal authority to stop it? I don't think they do. The course of action would be to prosecute for abuse of the exemption. Like Gary, I don't know what the penalty for that is, but I guess it's akin to or the same as unauthorised work to a TPO'd tree.
I am pretty sure the courts are satisfied that tree owners do not have to anticipate and prevent actionable nuisance (except subsidence cases, which are deemed negligent because foreseeable, the question of measurable damage being self evident). Nuisance is after all in the eye of the beholder.
I am baling out in case I have to look through Perrin again, which I never want to have to do.