http://www.legislation.gov.uk/ukpga/1972/20/section/29/enactedRoad Traffic Act 1972Road traffic offencesVehiclesRoad safetyDriving licencesHeavy goods vehiclesKing's Printer of Acts of Parliament2019-12-02 PART I 29 If, while a motor vehicle is on a road or on a parking place provided by a local authority, a person otherwise than with lawful authority or reasonable cause gets on to the vehicle or tampers with the brake or other part of its mechanism, he shall be guilty of an offence.