VAUXHALL'S all-new Astra GTC has arrived in showrooms, poised to become the most popular vehicle in its class.

It replaces the Astra Sports hatch, which in 2007 and 2008 out-sold its nearest competitor by three-to-one, and up until last year was still the clear leader with sales totalling 11,451.

The manufacturer says the GTC mainly competes against the Volkswagen Scirocco, the Renault Megane Coupe and the three-door Audi A3.

However, given the GTC's premium design and sophisticated underpinnings, Vauxhall also expects the BMW 1-Series to be potential competition.

Vauxhall's traditional rival, Ford, has already announced there will be no three-door Focus, giving the GTC a real advantage in this arena.

Offering a heady mix of dynamic excellence, dramatic design and competitive pricing, it is available in Derby through Pentagon Vauxhall.

There are Sport and SRi versions priced from £18,495, which is nearly £1,350 less than the basic version of the Scirocco.

Since the Astra GTC shares no body panels with either the Astra hatch or sports tourer, it has a unique appearance in the range and one which has largely stayed faithful to the stunning GTC concept car displayed at the 2010 Paris Motor Show.

"We wanted the Astra GTC to be the ultimate expression of Vauxhall's design language, and to embody our passion for the motor car," said Mark Adams, Vauxhall's British-born vice president of design.

"But we didn't want emotion to get in the way of functionality: the Astra GTC still needed to be clever, practical and affordable," he added.

The only exterior design features shared with the Astra hatchback and sports tourer are the door handles and the roof aerial.

Mark set out to create a car punching well above its class above and he has achieved his aim with a vehicle that has a low, wide stance and simple, yet rakish lines.

The car is offered with 1.4 and 1.6-litre turbocharged petrol engines plus 1.7 and 2.0-litre diesels.

The most potent power plant is the 16-litre turbo petrol engine which produces 180PS and achieves a specific output of just over 100PS per litre.

Available across the range, the 1.6 turbo is the most powerful series production engine in its displacement class.

Its high power is matched by an impressively wide plateau of torque, with 230Nm available from 2,200rpm to 5,400rpm.

With this engine, the GTC can accelerate from 0-60mph in 7.8 seconds, and on to a top speed of 137 mph.

The diesel engines have common rail, multiple fuel injection with the 1.7-litre power plant available in two states of tune, providing either 110PS and 280Nm of torque, or 130PS and 300Nm.

Combined cycle fuel consumption for both is 62.8mpg with standard wheel rims fitted, and each achieves 119g/km thanks in part to having a start/stop system fitted as standard.

An ecoFLEX version of the GTC will also have this engine with emissions of just 109g/km.

The most powerful diesel in the car is the 2.0 CDTi, which produces 165PS with an exceptionally strong 350Nm of torque from just 1,750rpm. This helps it achieve a 0-60mph time of 8.4 seconds and 50-70mph in 6.4 seconds, together with a combined fuel consumption of 58.9mpg and emissions of just 127g/km (18 and 19-inch wheels fitted).

Again Vauxhall's start/stop system is fitted as standard to the vehicle.

Six-speed manual gearboxes, offering a wide spread of ratios, and a tall, fuel-saving top gear, are standard fit across the entire range.

All gearboxes include triple cone synchronization on first and second gears for easy engagement, and a synchronized reverse gear.

A six-speed automatic gearbox is also available in the case of cars with the 1.4 Turbo 140PS and 2.0 CDTi 165PS engines.

Even in entry-level trim, the Astra GTC adopts the sophisticated HiPerStrut front suspension derived from the Insignia VXR, offering precision handling and unmatched stability.

Choose an SRi version and hill start assist also comes as part of the deal to prevent you rolling back on a slope by keeping the car's brakes applied until just the right moment.

Dual front seatbelt pre-tensioners and a pedal release system are standard on all GTCs, along with front, side and curtain airbags.

Adaptive forward lighting and front and rear parking distance sensors are available at extra cost.

The lighting deal includes dark-style bi-xenon lights, LED daytime running lights and high-pressure headlamp washers. Eight light settings are selected automatically depending on road and weather conditions.