Sadly some Hungarian berry pickers showed up. A big thank you to the bird ringer (apologies I didn't catch your name) who talked to them whilst I phoned the police; who weren't overly interested unless the situation got out of hand. The berry pickers eventually left, only getting two trees at the far right side of the car park. Beware Hungarian's brandishing large sticks and nets!
(This picture is uncropped just to show how close they got)