HYBRID-powered versions of the Vauxhall Vectra and Astra are being proposed as part of ambitious plans by General Motors to sell more than one million of the low emission cars a year globally by 2007.

Rick Wagoner, chief executive of GM, announced the dramatic move at this year's Detroit Motor Show. He gave the green light to launching three types of hybrid system across at least seven of the high-volume car and truck ranges built by the world's biggest motor company.

The environmentally-friendly and fuel efficient versions of the best-selling UK models will go into the showrooms if interest in hybrids becomes sufficiently strong to spur GM into head-on competition with new eco models from Japanese manufacturers.

Officials admit they are keen to respond to cars like the Honda Insight and Civic Hybrid and Toyota's Prius, which achieve ultra-low exhaust emissions by teaming electric motors with traditional internal combustion engines.

GM will begin to roll out its ambitious plan later this year when it starts supplying fleet customers in the US with hybrid models.

Wagoner said: 'We might increase the number of vehicle models to 12 if the demand is there – we want to go to the volume heart of the market. The option of hybrid power on trucks, sport utility vehicles and mid-size cars is a major commitment to consumers. Although today's hybrid market represents relatively low volumes, we are well placed to meet market demand as it develops.

'In fact, if customers go for the hybrid option on all the vehicles in our multi-year plan, demand could eventually exceed one million units each year.'

Wagoner described GM's approach to hybrid propulsion – regarded by Japanese car firms as a viable alternative until fuel cell technology becomes widespread – as pragmatic.

He added: 'This is a matter of both competitive positioning and good long-term business planning. It might be uncertain as to what level of market may exist for hybrids right now, but we think this technology has the potential to become a factor in the market.'

The firm confirmed that development could include the Epsilon (Vectra) platform and the Delta platform that is being developed for the new Astra, due to be launched in 2004.

But a Vauxhall spokesman added: 'We will continue to focus on improving our line-up of diesel engines and the first move in this direction is due in March when a new version of the Astra's 1.7-litre, 80bhp unit will comply with Euro IV emission regulations.' Vauxhall is set to be the first manufacturer to offer Euro IV compliant engines, which are exempt from a 3% company car tax supplement applied to diesels that do not meet the stringent emissions standard.