Quote:
"Electric and petrol-powered micro-scooters are not, and never have been, road legal in the UK. Recent court rulings have imposed heavy penalties on users, treating the machines as small motorcycles in law. Thus, riding an electric scooter in a public place (a public road, footpath or cyclepath) can result in prosecution for riding without insurance, MOT, tax, and a BS-standard motorcycle helmet, resulting in hefty fines and (according to a number of recent cases) points on your driving licence."
Source:
http://www.atob.org.uk/electric_legal_.htm
Answer to your question:
On private land, with the permission of the landowner, and nowhere else.
Chris