Former Government minister Michael Meacher has claimed that the war on terrorism is a "political smokescreen" allowing the US to dominate the world and its oil supplies.

Writing in The Guardian, Mr Meacher, who was environment minister for six years until June, argued that the US knew in advance of the September 11 attacks but did not act for strategic reasons.

It has since made "no serious attempt" to catch Osama bin Laden, he added.

His comments provoked a strong reaction from the US embassy in London, with the paper quoting a spokesman saying: "Mr Meacher's fantastic allegations - especially his assertion that the US government knowingly stood by while terrorists killed some 3,000 innocents in New York, Pennsylvania and Virginia - would be monstrous, and monstrously offensive, if they came from someone serious or credible."

Mr Meacher, MP for Oldham, claimed that "the truth may well be a great deal murkier" than the conventional explanation that, after the September 11 attacks, the US launched a global war on terrorism, striking first at al Qaida bases in Afghanistan and then, because Saddam Hussein was alleged to have weapons of mass destruction, going to war with Iraq.

He cited a document called Rebuilding America's Defences, written in September 2000 by neo-conservative think tank Project for the New American Century, which was set up by a group including Dick Cheney, Donald Rumsfeld and Lewis Libby (Mr Cheney's chief of staff).

The PNAC plan "is a blueprint for US world domination" which "provides a much better explanation of what happened before, during and after 9/11 than the global war on terrorism thesis", he wrote.

"From this it seems that the so-called 'war on terrorism' is being used largely as bogus cover for achieving wider US strategic geopolitical objectives."

He said the PNAC document stated that making the US "tomorrow's dominant force" would be a long process without "some catalysing event - like a new Pearl Harbour".