The Toyota Prius plug-in hybrid has been rated as releasing less than 60g/km of CO2, meaning it will be the cleanest car on the roads when it becomes available for leasing next year.
The car, which was unveiled at the Frankfurt motor show, also has a 12.5-mile electric range (six miles further than the conventional Prius) at speeds up to 62mph, before switching to conventional petrol-electric hybrid operation.
Toyota's research has shown that 80 per cent of UK journeys are less than 6.2 miles long, meaning an electric-only journey would be possible.
The plug-in Prius will be the first Toyota to use lithium-ion batteries, which are smaller, lighter and hold more charge than the nickel metal hydride cells the company has used to date.
The plug-in Prius can be fully recharged from a 230V power supply in 1.5 hours.
Next year's test programme will involve 500 customers worldwide leasing the car and putting it through everyday use. Around 150 plug-in Prius's will be tested in Europe, including some in the UK.
Details of UK tests will be announced at a later date.