Motorists are being warned that there's a certain situation where sitting in the passenger seat and fiddling with a phone could land them in trouble.

That's because you don't actually have to be driving to be legally responsible for the vehicle.

If you are instructing a learner you are responsible for the car - therefore all road laws that apply to you while driving apply to you as an instructor in the passenger seat, reports the Express .

So you could face the punishment if they are using a phone while supervising a learner of up to £200 and six penalty points.

This applies to both professionals and friends and family teaching someone to drive.

Neil Greig, IAM RoadSmart director of policy and research, said: "Supervising a learner actually puts you in the driving seat so legally you must treat it in the same way as if you were behind the wheel.

"Learning to drive is stressful enough without a passenger beside you who is more worried about posting than parking."

Certain road laws will, however, not apply to the instructor while supervising a learner.

For example, if the learner breaks the speed limit, it will be their licence that receives the fine and penalty points and not the instructor.