You need a code A1 licence for the vehicle. I copy the legislation for you.
“motor vehicle” means any self-propelled vehicle and includes—
(a) a trailer; and
(b) a vehicle having pedals and an engine or an electric motor as an integral part thereof or attached thereto and which is designed or adapted to be propelled by means of such pedals, engine or motor, or both such pedals and engine or motor, but does not include—
(i) any vehicle propelled by electrical power derived from storage batteries and which is controlled by a pedestrian; or
- any vehicle with a mass not exceeding 230 kilograms and specially designed and constructed, and not merely adapted, for the use of any person suffering from some physical defect or disability and used solely by such person;