The Big Cat is taking another radical leap forward – and in an amazing exclusive, Auto Express has the pictures to prove it!

Following hot on the heels of the XF, Jaguar’s S-Type replacement, the British firm is set to reveal an even more dramatic model in the shape of this new flagship, the XJ.

The newcomer has one aim – to beat the Audi A8, BMW 7-Series and Mercedes S-Class at their own game. And with gorgeous looks, a fabulous driving experience and Jaguar’s first-ever hybrid powerplant, the new XJ is set to propel the marque back to the top of the luxury saloon class.

Under the skin, the saloon will use an updated version of the current car’s aluminium chassis. The wheelbase will remain virtually identical, so improvements in space will come from mounting the rear seats lower – to give better headroom – as well as the use of sculpted front seatbacks, which boost legroom.

Major updates will be made to the dashboard, with a facia modelled on the XF’s. That means it will feature touchscreen displays, motion-sensing controls and Jaguar’s new DriveSelect rotating gear selector, which rises from the transmission tunnel when the ignition key is turned. As with the uncluttered exterior, the cabin will be simple, with high-quality woods and leathers, and plenty of cool blue mood lighting.

Key to the XJ’s appeal will be the fact it debuts Jaguar’s hybrid technology. This uses super-capacitors – small, high-power batter-ies – to boost engine performance, and includes advanced stop-start technology to help reduce fuel consumption and emissions of the entry-level 3.0-litre V6.

Every powerplant will be revised, though, with a flagship R model being fitted with a new 500bhp 5.0-litre supercharged V8, while the 3.0 V6 petrol features a supercharger, too. The capacity of the current model’s twin-turbo V6 diesel is also set to increase from 2.7 litres to 3.0 litres.

All engines are mated to Jaguar’s latest six-speed automatic box, complete with steering wheel-mounted paddles. The XJ will also have a new damping system similar to Audi’s Magnetic Ride. This can react quickly to changes in road surface, and works with a stiffer body, wider track and revised suspension to give the Big Cat class-leading ride and handling.

The XJ is the latest example of Jag-uar’s product renaissance, and takes its styling cues from the XF. Now that car is finished – sales of the saloon kick off in March next year – the XJ is the brand’s most pressing project.

The current generation arrived in 2001, and although it’s still great to drive, improvements are needed to its engine range, cabin packaging and interior design. As you can see from our images, the XJ is facing a bright future. It draws on the C-XF concept, which was described by Jaguar as “a precursor to cars that will become recognised for their groundbreaking exteriors”, and the model is clearly the next step for the firm.

It has been designed under the guidance of Ian Callum – the man who penned the XK and the XF – and the flagship will get a recessed grille with striking twin-lamp LED headlights.

The bonnet is marked out by a central power bulge, but the most distinctive styling cue is the low roofline which, combined with minimal glass areas and a radical coupé-like profile, results in a long, low and menacing look. The production version will also get a panoramic glass roof. It’s widely known that Callum is a fan of the original Jaguar Mark X of the Sixties – and the new XJ takes inspiration from that classic model.

Expect to see a concept version of the XJ towards the end of next year, with sales starting in mid-2009.