It is one of motoring's most popular myths and it has now been fully debunked.

Many motorists believe driving with the internal or reading lights on is against the Highway Code but after a thorough examination and a check with The Mirror's motoring experts we've discovered it isn't.

The rules are that you can’t show anything out of the back windscreen of a car other than a red light, and the driver must not be distracted from the road.

However, there’s nothing that fundamentally bars the interior light from being switched on, and the general consensus seems to be that it’s fine.

A spokesman for the The RAC said: “There is no law against this [interior light]. However, if a police officer pulls you over and adjudges your interior light to be a driving distraction they have the right to tell you to turn it off.”

A police officer, who wished to remain anonymous, said: “The only scrap of a chance may be if the interior light is white AND it is showing to the rear (which I would doubt) so that it is visible from outside the rear of the vehicle.

"The offence there is ‘showing a light other than red to the rear'.

Now you know

“When you think about it a car has numerous lights within the cockpit nowadays, one more located in the roof probably won’t make much difference. (Sat-navs, instrument dials, radios etc).”

Kids, if you're reading this, when dad scares you into turning that light off, let him know it's all okay.

Just don’t forget to turn them off when you get where you’re going, or you’ll run the car battery flat. Dad won’t be too impressed then.

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