The warning came from James Woolsey, a former CIA chief and now chairman of the US Clean Fuels Foundation, to members of the SMMT in London.

Woolsey launched a blistering attack on the US government for investing in what he views as the wrong technology and criticised California governor Arnold Schwarzenegger's move to establish a so-called Hydrogen Highway of refuelling stations in the state.

“Hydrogen and fuel cells are not the way to go. The decision by the Bush administration and the State of California to follow the Hydrogen Highway is the single worst decision in the past few years,” he said.

“In the meantime you have to bring down the cost of a fuel cell vehicle by a factor of about 40 to make it affordable,” he said.

Woolsey estimated that a hydrogen infrastructure will cost the US $1 trillion and argued that investments in other technologies, including hybrid-electric plug-in vehicles, would be more cost-effective and achievable.

He argued that 78 per cent of US cars clock up less than 40 miles a day and could be recharged overnight during off-peak hours.

“The important thing is that there should be no single solution or decision by governments,” he said.