Car seats may not protect young children from serious injury or even death during a collision, research suggests.

A study by UK scientists has found huge variations in the level of safety provided by the country's 20 best-selling car seats.

While some seats comfortably passed rigorous safety checks others only scrapped through and one actually failed the test.

Top performers

Mothercare MX Sport Britax Eclipse Britax Cruiser Plus Britax Renaissance Graco Cosmic Recaro Start Mothercare Paul Vogel

The scientists said the findings highlighted the need for parents to choose carefully when buying a car seat for infants or toddlers.

Official figures show that 570 children are killed or seriously injured in cars every year in the UK.

Experts believe two out of three of these deaths or injuries could be avoided by using child seats.

Scientists at the Transport Research Laboratory in Berkshire said they strongly supported the use of child seats in cars.

Choose carefully

But they said it was important that the seats provided high levels of protection for children and were easy for parents to use.

They tested 20 different seat models. Each seat was subjected to front and side impact collisions at a speed of 30mph.

Under European law, all child seats must undergo front collision tests. However, there is no similar requirement for them to withstand side impacts even though these are estimated to case 20% of all child deaths in cars.

The UK study found the some models failed to give adequate protection to the child's head while on actually broke under the strain of one simulated impact.

The scientists also examined how easy the seats where to use. Figures suggest that 70% of seats are not fitted correctly in cars or are not used properly increased the risks of injury for children.

Single standard

The findings, published in What Car? magazine, have prompted calls for a new international standard for child car seats.

What Car? editor Rob Aherne said: "While we were pleasantly side by the side-impact results, the overall scores have highlighted the need for an international standard," he said.

"As things stand, the EU regulation allows different testing houses to test seats at different levels, which brings a lack of consistency to the final results.

"We are therefore backing the implementation of a single global testing standard. That way consumers will know exactly how safe the seat they are buying is."

The magazine, scientists from the transport research laboratory and child seat manufacturers, are now hoping to garner support for what they are calling a New Programme for the Assessment of Child Seats.

They are aiming to have new tests for child seats under way within two years. These checks will include tougher standards for front, side, rear and angled impacts, with the aim of superseding current regulations.

Mothercare, which manufacturers and sells car seats across the UK, welcomed the study.

A spokesman said: "At Mothercare, our commitment is to only stock merchandise that is safety tested and all Mothercare and branded products sold in Mothercare stores go through rigorous testing procedures.

"We are working with What Car? to pioneer new levels of testing which will ultimately improve the safety of all our car seats and those of other retailers."