The Vauxhall Astra is now available with the firm's BiTurbo engine which first appeared in the three-door Astra GTC and family Insignia.

The 192bhp performance diesel with 400Nm of torque will be fitted to the five-door hatchback and Sports Tourer estate by the end of the year.

As Vauxhall's most powerful diesel, both models will reach 60mph in less than eight seconds, with a top speed of 135mph-plus while achieving 55.4mpg and 134g/km CO2. Stop-start technology is also standard.

The new derivatives get a recent style refresh found across the Astra range. This includes a revised front grille, new front indicators and fog lamps and revamped rear-panel styling.

And the BiTurbo models also come with 18-inch alloy wheels, twin rear exhausts, exterior styling pack and alloy sports pedals.

Available to order now, with first deliveries expected late 2012, prices start from £24,095 for the hatch BiTurbo and from £25,110 for the Sports Tourer.

Built at Vauxhall's Ellesmere Port plant in Cheshire, it was confirmed earlier this year that General Motors would invest £125m in the factory following fears it would be shut down. But with the next generation of Astra models secured for the facility, 700 new jobs as well as a £1bn investment into the UK's car component industry is expected.