AOPA UK does vigorously and effectively protect its members against threats to aerodromes, airspace and ratings, so I've no doubt that it will respond to this threat now that the Department for Transport has drawn attention to it.
Few UK pilots are eligible for full legal aid, so the CAA counts on few of its accusations being defended. Of charges that are tried, the CAA loses more than half according to its own figures.
AOPA USA offers affordable optional insurance for legal expenses to defend civil and criminal cases, and I'm sure that most of the British flying associations will be considering something similar now that the Genie is out of the bottle.