In reply to JackFuller:
Get yourself over to either the MSE or PePiPoo forums for advice before you respond. I'm reasonably certain that the signage is not compliant with PoFA 2012 and they won't be able to hold the keeper of the car liable but you'll want experts to look it over.
I have to admit I'm slightly surprised that they're bothering to send someone to ticket cars; I'd believed the business modern here was stick up a single sign and rake it in from the app with no further effort (because if they are intending to issue tickets they usually do a better job of putting up compliant signage).
