The new rules over the manufacture of child car booster cushions have come into force a week early.

Originally due to come into effect on March 1, the new law means manufacturers are not allowed to sell backless booster seats for smaller children.

However, parents who already own one will still be able to use them for children weighing more than 15kg (2st 5lbs).

The forthcoming rules mean children using new seats will have to weigh more than 22kg and be taller than 125cm.

They are to be brought in after the United Nations warned booster seats without backs are not safe for smaller children because they do not protect against side-on collisions.

Data obtained by the price comparison website confused.com suggest that only 66 per cent of parents do not fully understand the current booster seat height, age and weight regulations.

Freedom of Information requests by the company suggest there were 4,600 incidents where UK drivers did not adhere to child seatbelt laws in 2015.

More than 19,000 offences were recorded between 2013 and 2015.

So if you have a young child, this is what you need to know: Your child must sit in a car seat until they are 12 years old or 4’5” tall, depending on which comes first.

The seat can be rear- or front-facing if your baby is older than 15 months, but for those first months of life, a baby must face the back of the car.

Once the top of their head is level with the top of the seat, it’s time to get a bigger one - according to experts, this should only be done when your baby can hold their own head up for at least half an hour at once.

If your baby weighs less than 9kg, they should travel in a baby carrier rather than a child seat.

Once your child is older and bigger, you an sit them in a backless booster seat, but only when they weigh about 15kg, which is usually around the age of three and a half.