Kent Road Safety said: “For those of you that are grandparents, did you know that by Law children have to travel in a high-backed booster seat until they are aged 12, or reach 135cm in height – whichever comes first?

“But what about smaller children? There are lots of retailers who should be able to help you. 

“Did you know rearward facing is far safer and can be used for children up to 4 years old in some circumstances?

“Do your research. Rear-facing can protect the child’s neck, head and internal organs in the event of a collision.

“Please remember your children or grandchildren trust you to keep them safe.”

According to the Royal Society for the Protection of Accidents (RoSPA), there are only a few exceptions for children not to be in car seats. 

The law states children above the age of 3 can travel in cars without a proper booster seat over short distances in an “emergency or unplanned situation”.

Travelling in taxis also offers some protection to the rule while carers with multiple younger children are also given some leeway. 

According to RoSPA, if it is not possible to fit three child car seats in the rear of a vehicle, only “two children up to 135 cm in height must travel in child seats.”

Meanwhile, the third child may use an adult seat belt on its own as long as they are over three”.

However, the rules offer little wiggle room with road users set to be severely punished if they are caught out.

Breakdown experts and car insurance specialists at the RAC stressed fines could be as high as £500 in a major blow to cash-strapped Britons. 

The RAC explained: “Selecting the right child seat will give your little one the best possible protection in the event of a crash, that’s why it’s important to understand current child car seat laws and the correct way to install one.

“It’s also important to note that you risk a £500 fine if you’re caught using an unsuitable or incorrectly fitted car seat.”