US car giant Ford has been criticised by industry body Thatcham Research after its Mustang sports car achieved just two stars in official European crash tests.

The Euro New Car Assessment Programme (NCAP) puts all new cars through thorough crash tests and awards them a star rating out of five.

Recent changes have made it tougher for new cars to achieve high scores in the test – but the Ford Mustang has become the first car from a top 10 manufacturer to achieve just two stars since 2008.

“This really bucks the trend,” explains Matthew Avery, the director of research at Thatcham, the independent company responsible for crash tests in the UK.

“Car buyers are increasingly benefiting from improved safety functionality and features, and this applies equally to cars in the sports roadster category as to family cars. We have concerns about the Ford Mustang’s crash protection of adults and children which also makes it unsuitable for having rear passengers.”

The sixth generation Ford Mustang marks the first time the American pony car has officially been sold in the UK. It’s proving to be popular, with more than 5,000 sold in the UK since it went on sale in 2015. This makes it the best-selling sports car on sale – ahead of the pricier Porsche 911 and Jaguar F-Type.

But Thatcham says that important safety systems that are available in the USA – including autonomous emergency braking – aren’t available in the UK.

Systems like this are already available on the affordable Fiesta, and Ford says it will be introducing them on the Mustang when it’s revised (and re-tested) later in the year.

The Mustang scored a reasonable (but not outstanding) 72% rating for adult occupants, but was let down by child occupant tests (in which it scored 32%) and for its shortage of safety assist features (it scored just 16%).

During the tests, a lack of seatbelt pre-tensioners and load-limiters saw a dummy rear passenger sliding under the seatbelt in a frontal offset test. The Mustang was also criticised for its airbags failing to inflate sufficiently to protect passengers.

A Ford spokesman told automotive publisher Motoring Research that the Mustang was “fundamentally a safe car”, pointing out its five-star NHTSA NCAP rating in the USA. The company also described the Euro NCAP ratings as having “a very strong focus on family car safety characteristics.”

Euro NCAP results for the new Volvo S90 and V90 models have also been released today – both of which achieved five stars and were praised for their class-leading safety.

“It does make you wonder if anything rubbed off on Ford from the Volvo/Ford partnership,” added Avery.