I noticed from the CAA website that for 2006 there were a few prosecutions for infringements. Clearly the exact details are not disclosed, but under what conditions generally is a procecution sought.
I would have thought that no one would intentionally enter without clearance and given that assumption then if the below infringements were accidental, under what circumstances will the CAA prosecute.
Class A infringement Guilty plea Fine £600
Class A infringement Guilty plea Fine £500
Class D infringement Guilty plea Fine £750
Aerodrome Air Traffic Zone Infringement Guilty plea £250
Aerodrome Air Traffic Zone Infringement Guilty plea Fine £800