Gordon Brown went "green" yesterday as he took a ride on Europe's first biodiesel train.
The prime minister-in-waiting travelled from London's Euston Station to Chester on a Virgin Voyager train which was starting a six-month trial using a blended fuel which is 20 per cent biodiesel.
Virgin has a special concession which means that the company is only paying 7p a litre in tax to use the biodiesel rather than the normal 54p a litre.
Before travelling on the train with Mr Brown, Virgin boss Sir Richard Branson called for a reduction in tax on clean fuels.
And when asked about the tax situation, Mr Brown replied: "If this scheme works well we are prepared to look at other things. We are prepared to look at what could be done in the future.
"We have to prove that this works. If it works I want other train companies to consider using biodiesel."
Mr Brown said he was delighted that biodiesel was being used on trains.
He went on: "I want Britain to be a world leader in the development and use of environmentally-friendly fuels and I believe they will play a fundamental part in our efforts to reduce emissions and tackle climate change."
Yesterday's first biodiesel train, terminating at Llandudno in Wales, left on time at 11.27am.
The biodiesel element of the blend is derived from rapeseed, soy bean and palm oil and Virgin is hoping that if the trial is a success it can convert its voyager fleet to run on biodiesel thus cutting carbon dioxide emissions. Virgin believes that the move could be the equivalent of taking 23,000 cars off the road with 34,500 tonnes less C02 being emitted into the atmosphere each year.
During the trial the biodiesel train will run across much of Britain, from Birmingham to Scotland, in south Wales, north-east England, north-west England, the West Country, South-west England and the south coast.
Sir Richard said: "It's fantastic we are leading the rest of Europe in developing this fuel. The tax on clean fuels is, quite bizarrely, higher than on dirty fuels. Our indications are from Gordon Brown that he will address this problem. If it's not addressed we will have dirty fuels and the clean fuels will move abroad."
Virgin is conducting the trial in conjunction with the Association of Train Operating Companies and the Rail Safety and Standards Board. Biodiesel is a processed fuel derived from biological sources which is biodegradable and produces less C02 than conventional diesel.