UK laws do not allow any electric bike with twist-and-go throttle. A throttle assist allows users to thrust the bike forward using the turning motion on the handlebar.
The UK only permits electric bikes that have a pedal-assist motor.
https://eskute.co.uk/blogs/news/elec...assist%20motor.
Pedal assist is legal until you chip them or move the magnet to derestrict them, although harder to spot because they look more like a normal bike and you still have to pedal.