Wow! New legislation has just been passed to fit speed limiters to all new cars from 2022.
The mandatory speed limiters will be introduced at the same time as a raft of other safety equipment, which includes data loggers, autonomous emergency braking, lane keep assist, a driver fatigue detection system, reversing sensors or cameras, and pre-wiring for alcohol interlock devices. All new models given type approval from May 2022 onwards will be required to have these systems, while models on the market prior to that date must have them by May 2024.
Doesn't look like it applies to bikes as yet!