The new Vauxhall Astra VXR will become Britain’s fastest-ever hot hatch when it goes on sale next June. It is expected to cost under £20,000. Powered by a 2.0-litre, turbocharged four-cylinder engine pumping out 240bhp, the hottest-ever Astra will beat its hot-hatch opposition with a 155mph top speed: the sort of figure usually associated with high-performance saloons from BMW, Mercedes and Jaguar.

The current crop of hot hatches, such as the Alfa Romeo 147 GTA, Renault Mégane Renaultsport 225 and Honda Civic Type-R have top speeds below 147mph, and even a high-output saloon like the Subaru Impreza WRX could only record 141mph in an Autocar road test. VW’s scorching new Golf GTi claims a 145mph top speed.

The VXR will be previewed at the Paris Motor Show this week as the Opel Astra High Performance Concept – as seen in these photographs – and will be revealed at the same time as the other Astra three-door models. The production VXR will follow the aggressive look of the concept car, but differ in some essential details.

‘This is the first of the volume VXR models and we really want to get this car right,’ said a Vauxhall spokesperson. ‘We’re pushing to get every detail just as we want.’

In the concept, the swooping three-door Astra’s coupé-like profile has been beefed-up with 19in wheels, a purposeful bodykit with new front and rear bumpers, wheelarch extensions, sill mouldings and a new body-coloured grille. Unusually-shaped trapezoidal exhausts complete the package.

However, Vauxhall’s version will differ from the concept. Most obvious will be a vee-shaped grille in either body-colour or black, but the VXR will also have more aggressive bumpers, tipped to be even more sculpted with wider air inlets and outlets. Vauxhall is even looking at bigger and re-shaped exhausts for the production version.