President George Bush, long criticised by environmentalists for being the "toxic Texan", outlined his plan yesterday for hydrogen-fuelled cars that would reduce pollution and America's dependence on foreign oil.

In a speech aimed at Congress, Mr Bush asked lawmakers to "think beyond the normal" and approve his plan to spur development of clean-burning hydrogen fuel cells. He has requested that $1.2bn (£730m) of federal money be set aside over the next five years for research into the engines.

"What we do today can make a tremendous difference for the future of America," he said, detailing a proposal he first mentioned in the State of the Union speech. He promised "a new national commitment" to take fuel-cell powered cars from the laboratory to showrooms within the next 20 years.

Mr Bush was met at the National Building Museum in Washington, where he made the speech, by protesters demonstrating over his energy policies, in particular his highly controversial plans to drill for oil in the Arctic National Wildlife Refuge in Alaska. "Caribou Not Oil" said one protester's placard.

Critics have said hydrogen-powered cars will not be widely available and affordable for a generation. They have questioned Mr Bush's short-term energy policies.

A year ago, the administration announced a 10-year programme to help car manufacturers to develop fuel-cell technology to replace the internal combustion engine.

A fact sheet produced by the White House admits that hydrogen is still four times as expensive as petrol and that fuel cells are 10 times more expensive to build than a conventional engine.

But it predicts that by 2040, the hydrogen fuel-cell initiatives could reduce annual greenhouse gas emissions by more than 500 million tons of carbon equivalent each year and reduce consumption of oil by 11 million barrels a day.