Four out of five of the UK’s best selling cars are susceptible to keyless theft, it has been claimed.

The Ford Fiesta, VW Golf, Nissan Qashqai and Ford Focus, which between them accounted for 261,759 new registrations last year, were all found to be vulnerable to so-called relay attacks, according to consumer group Which?

Only the Vauxhall Corsa, the country’s third biggest seller was immune to the risk because it is the only one not available with a keyless entry system.

The report comes as new government data reveals that car thefts have risen 40% in the last five years, with almost 112,000 cars stolen in 2017-18.

Which? analysed data from the General German Automobile Club (ADAC) to find out the impact of keyless attacks on the five best-selling cars in the UK in 2018.

ADAC tested 237 cars with keyless systems and found that only three – all from Jaguar Land Rover – could not be compromised.

230 of the cars tested, from more than 30 brands, could be unlocked and started using relay boxes while another four could be either unlocked or started.

Only the Jaguar i-Pace, Land Rover Discovery and Range Rover were found to be protected from such attacks.

“The fact that so many cars on the road are susceptible to keyless theft simply isn’t good enough. We want manufacturers to up their game when it comes to making their vehicles safe from theft.”

However, Mike Hawes, chief executive of the Society of Motor Manufacturers and Traders said new cars were “more secure than ever”.

He told the BBC: “Industry takes vehicle crime extremely seriously and any claims otherwise are categorically untrue.

“Criminals will always look for new ways to steal cars; it’s an ongoing battle and why manufacturers continue to invest billions in ever more sophisticated security features.”

Several manufacturers also emphasised that they were working on ways to make cars more secure and that the risk of car theft remained low.

The system on some models can be deactivated by a dealer and BMW and Mercedes have added motion sensors to their key fobs so they don’t send out a signal when they are not moving.