Motorists who supervise learner drivers might be risking their own licenses due to a widespread ignorance of the rules governing informal practise sessions on the public road.
An AA/Populus survey discovered that many experienced drivers were not aware that using a mobile phone or failure to wear their glasses whilst in the passenger seat was illegal when a learner was behind the wheel.
The motoring organisation said that practise with friends and family could provide invaluable experience of the road, but that some of those supervising failed to realise that the law considers them to be in control of the car.
The AA highlighted one case where a motorist was imprisoned after the learner driver in their care was involved in an accident which left two people dead.
Almost a quarter of the 19,000 people surveyed did not realise it was illegal to use a phone and 13 per cent were unaware that they must be wearing the glasses they use for driving whilst supervising. Incredibly, almost one in ten didn't know that falling asleep was also against the law.
AA Driving School director Simon Douglas said: "Learners who build on skills they gain in formal lessons by practising with family or friends have a better chance of passing their test and are likely to be safer behind the wheel.
"Many are passing on bad driving habits or even risking a run-in with the law."