These are the first pictures of Land Rover’s 145mph Range Rover Sport undisguised, sneaked out from the company HQ. The chunky profile and sporty stance of Land Rover’s £35,000 five-seat BMW X5 and Porsche Cayenne-chaser is clearly visible, as are its flared wheelarches and big wheels.

Despite the performance-oriented chassis, Land Rover is understood to be positioning the Range Rover Sport as a luxury grand tourer, rather than a sporty 4x4 like the X5. ‘It will surprise a lot of people, but we have to keep chassis refinement and good ride quality, too,’ said one engineer.

The pictures also reveal the Sport’s resemblance to previous generations of Range Rover. And it sits on a new 108in (2.7m) wheelbase, the same as the second-generation Range Rover.

The detailing, however, is very up to date. The three-bar grille has perforated slats in titanium-finish plastic, a reference to the current Range Rover, while the headlights feature the distinctive ‘twin-pocket’ design that’s become a Land Rover hallmark, and there are wing-mounted air intakes on both sides of the car, in contrast to the new Discovery.

The ‘floating’ roof is a major styling feature. It’s defined by the wraparound glass and black rear pillar – disguised on the cars in our pictures. The original 1970 Range Rover used this feature.

Under the skin is a short- wheelbase version of Land Rover’s T5 platform (found under the new Discovery) with its integrated body-on-frame construction, all-round wishbone suspension, air springs and low-ratio transfer gearbox.

Three engines will be offered from launch next May – a range-topping supercharged 400bhp 4.4-litre V8, a 295bhp 4.4-litre V8 and a 190bhp 2.7-litre V6 turbodiesel. All Range Rover Sports will be fitted with auto ’boxes – unlike the new Discovery, there won’t be a manual diesel.