The vehicle floor accessory retailer CarMats.co.uk has warned drivers not to make a simple mistake when taking their children back to school this September, else they risk a costly fine.

With many schools up and down the country returning after the summer holiday this week, many motorists will be picking up and dropping off their kids each weekday.

However, Ash Young, Founder of CarMats.co.uk, highlighted that those waiting to pick up their children remember to turn the engine off when it is not in use.

He advised: "Idling means keeping your vehicle’s engine running while it’s not moving, which releases harmful carbon dioxide (CO2) into the air.

"While idling can't always be avoided, it can often be prevented, especially at school gates. To reduce idling, try having your child ready to exit the vehicle with their school bags and lunch in hand, or consider parking further away and walking to the entrance."

Whether parents are waiting for their child's class to be dismissed in the afternoon or finding their PE kit and homework in the morning, idling the engine can help to keep the engine and interior warm.

Nevertheless, whilst it may feel convenient, unnecessarily idling an engine releases a significant amount of pollution into the air.

Previous surveys have found that idling for around 10 seconds produces more emissions than turning off and on the engine, in addition to wasting more petrol or diesel.

No matter the location, drivers who are caught idling unnecessarily can also face significant repercussions if they are caught.

If a police officer spots a motoring in an idling vehicle, they can issue a fixed penalty notice (FPN) of £20, which can increase to £40 if it is not paid within 28 days and £80 if that fine is ignored for over two weeks.

Many local authorities also allow residents to report others who idle their vehicles unnecessarily, which can lead to similar fines.

To help prevent being fined, owners of many modern vehicles should make sure that the stop-start function is switched on.

Usually identified by an icon showing a capital A surrounded by two arrows, start-stop will shut off the engine wherever possible to cut down on emissions and wasting fuel.

If a car does not have start-stop, drivers should try to turn off their engine if they are waiting in the same place for a minute or longer.