Cameron's new green credentials under fire

David Cameron's newly trumpeted "green" credentials came under fire yesterday on the eve of a speech committing his party to cutting pollution.

At issue is the Tory leader's choice of car. While his Lexus GS 450 is a sign of his ecological sensitivity, it is not as green as it might be, according to critics.

The new vehicle is a "hybrid", which uses environmentally sound electricity around town and petrol at higher speeds.

But Mr Cameron could have opted for a smaller, more fuel-efficient Toyota Prius, also a "hybrid".

Instead of the Prius, a government-provided vehicle, Mr Cameron has decided to lease the Lexus, also made by Toyota, at normal commercial rates thus saving the taxpayer money, but incurring the displeasure of green campaigners.

At 104g/km, the Prius emissions are significantly lower than the 186g/km given off by the Lexus.

Mr Cameron argued that the official hybrid might not be big enough. "My problem is that often when I go on tour, I have a lot of people in the car with me and I found when I used a Prius it meant we had to have two cars rather than one, so I don't think it would be very good for the environment."

Mr Cameron is to commit the Tories today to a target of cutting emissions to 100g/km from new cars by 2022 and from all cars on British roads by 2030.

The Conservative leader said that his new vision amounted to a "radical agenda for greener cars".

In an article in The Sunday Telegraph, Mr Cameron said: "I want Britain to be at the forefront of international efforts to build a new generation of motor vehicles that are much less environmentally damaging.

"Such a programme will include significant incentives to encourage the ownership of newer, greener vehicles."

The debate over vehicle emissions has involved the Chancellor, who is still driven around in his three-year-old, gas-guzzling Vauxhall Omega with a carbon emission count far in excess of the vehicle chosen by Mr Cameron - 276 g/km.

Gordon Brown has said that he will be opting for a Lexus when he needs to replace his official car, but to do so now would be a waste of taxpayers' money.

Politicians have been emitting considerable quantities of hot air on the issue over the past few weeks, according to Tony Bosworth of Friends of the Earth.

Instead of arguing about which car their chauffeurs should drive, they would all be better off going by train, according to the Government's Commission for Integrated Transport.

Comparing CO2 emissions for a trip from London to Manchester, the commission found that per passenger, normal cars emitted four times as much carbon dioxide as trains.

Even using the new hybrid vehicles, they would be responsible for nearly three times as much pollution as if they had decided to go by train.

Woe betide a parliamentarian who chooses to go by plane for domestic trips when a train journey might suffice. The commission calculates that on a trip from the capital to Manchester, an aircraft emits nearly twice as much CO2 per person as a gas-guzzling car. The shorter the journey, the worse the figure because take-offs and landings are particularly damaging to the environment.

Mr Bosworth said: "We need green cars to tackle climate change, but we must also change how we travel.