If it's your ball and you're losing, take it home with you!
Could ABC close the airfield?
Legally, if they do have the power, then closing it is an option. No services, no need for it. No runway for the locals to fly from.
Nobody in power at ABC is going to suffer from that. So do the decent thing, come to a deal with the club and redo their lease to avoid the crazy situation that brought about their ability to build the fence. If they don't go along with that, then close the airfield.
Once a new agreement has been reached, ops can carry on free from worries.
Another option might be to close it and sell the land to PK to allow him to run his own airfield. No TUPE no issues, no licence, little or no fire cover, no bull****, just a friendly GA Airfield, that might just break even.