What are the legal reguirements for someone helping a learner to drive?

The supervising driver must:

- be at least 21 years old
- held a full driving licence for a minimum of 3 years
- meet the minimum eyesight standards
- ensure the car is in a safe and legal condition
- ensure the car displays red L Plates (or D Plates in Wales) if a learner is driving
- car insurance must cover a learner driver