Highway Code Rule 246 (which relates to the provisions of Section 19 of the Road Traffic Act 1988):
"Vehicles with a maximum laden weight of over 7.5 tonnes (including any trailer) MUST NOT be parked on a verge, pavement or any land situated between carriageways, without police permission. The only exception is when parking is essential for loading and unloading, in which case the vehicle MUST NOT be left unattended"
Highway Code Rule 248 (which relates to the provisions of Regulation 101 of the Construction and Use Regulations and to Regulation 24 of the Road Vehicle Lighting Regulations 1989:
"You MUST NOT park on a road at night facing against the direction of the traffic flow unless in a recognised parking space"
http://www.direct.gov.uk/en/TravelAndTransport /Highwaycode/DG_069860
In many (mainly urban) areas, most parking matters have been 'de-criminalized' and are now dealt with by the local authority. In other areas, it's still the police (and/or traffic wardens) who deal with parking. Your local Community Constable is probably the best person the speak to. He/she will either speak to the driver directly or refer the matter to the appropriate people.
Chris