Which? says manufacturers should improve on minimum standards

It said 10 seats on the market in the UK did not pass 40mph crash test conditions or were difficult to install, increasing risk of injury.

Which? criticised makers for failing to exceed minimum European standards that demand seats withstand a 30mph crash.

Manufacturers said the products complied with safety standards that were continuously being tested.

Which? said it was disappointed that the 10 car seats it had deemed inadequate over the past two years are still on sale.

"Simply making child car seats safe enough to pass the minimum safety test is downright irresponsible," it added.

Phase out

Six of the seats are from British firms Britax - Cruiser Plus, Ranger and Trio - and Mamas & Papas - Navetta Carry Cot, Elan and Passaggio.

Which? said the other child car seats to avoid were the Concord Trimax X-Line, the Meggy Kombi, the Storchenmuhle Starlight SP and the Graco Junior Plus.

But Britax, Mamas & Papas, Concord and Graco were all praised for making other seats which are among the safest.

A Britax statement in response to the report said it was "continuously improving the safety standards, products are being updated and replaced".

It added: "As part of our commitment to achieving the highest standards of consumer safety and comfort, it is already planned to phase these [the three criticised seats] out of the Britax range over the coming six months with newer designs and features."

Mamas & Papas said all its products complied with the current level of safety requirements "which is subject to a regime of continuous testing and revision".

It added: "If the technical experts feel that current standards require revision, then Mamas and Papas will be happy to comply with any revised specifications immediately."