New Land Rover Defender and Isuzu D-Max models are too “aggressive” during head-on crashes, a safety watchdog has warned.

Euro Ncap said the 4×4 and the pick-up truck lost points during safety tests because of the “threat they pose” to other road users.

The Defender’s front structure was found to make it “an aggressive partner to a colliding vehicle”, while the D-Max caused “areas of high deformation” to a mobile barrier used during the inspection.

Euro Ncap’s testing regime was overhauled this year to penalise larger vehicles if they fail to offer more protection to smaller models during an accident.

Despite dropping points, the Defender and D-Max still scored the maximum safety rating of five stars.

Matthew Avery, director of research at Thatcham, which administers Euro Ncap crash tests in the UK, said: “The new-for-2020 tests are really driving a requirement for increased performance, and more aggressive cars like the Defender and D-Max are being identified and marked down as a result.

“The latest test results show some manufacturers are finding compatibility a challenge.”

Honda’s first pure electric urban car, the Honda e, was marked down in the frontal impact test due to the risk of injury to its own occupants.

Protection was rated “marginal” for the driver’s chest, knees and femurs, and “poor” for their lower right leg.

Mr Avery commented: “Although it scored a solid four stars, there were definitely issues with the Honda in terms of driver protection and the lateral impact with the child dummy.

“The far side excursion result wasn’t great and this is a vehicle that doesn’t have a centre airbag function which is surprising.”

Nick Rogers, an executive director at Jaguar Land Rover, said the manufacturer was “obsessed with functional safety and the protection of both the occupants and other road users”.

He described the five-star rating as “an incredible honour”.