Well done AOPA
AOPA UK is doing a good job on this subject. But I also know that it is not just AOPA, because the meetings with the Treasury have been a joint effort with other UK representative organisations such as the GA Alliance (covering most air sports associations such as the PFA, BGA, BMAA etc) and BBGA.
There is a dedicated group of people in the lower weight end of GA that work together across the various representative organisations to try and secure the right outcome for their members in this ever changing (and challenging) regulatory environment. AOPA rightly uses its publicity machine to inform its members of its success and progress. Other organisations (volunteers) have less time to push out the publicity, though it is covered in those associations' magazines.
There is much background work, meetings and negotiation going on quietly on many topics, not least Mode S in the UK.