We have asked our Neighbourhood Sergeant for advice. She confirms:

PCSO’s can give a vehicle a ticket if they are obstructing the footway as long as they can show some one was obstructed. If there is a vehicle fully blocking the pavement then the 101 number can be phoned and if there is a PCSO available, which there often is, one can come out and issue a ticket. I will let the PCSOs know to patrol the area in order to try and prevent future occurrences.