Michael Meacher, who served as a minister for six years until three months ago, today goes further than any other mainstream British politician in blaming the Iraq war on a US desire for domination of the Gulf and the world.
Mr Meacher, a leftwinger who is close to the green lobby, also claims in an article in today's Guardian that the war on terrorism is a smokescreen and that the US knew in advance about the September 11 attack on New York but, for strategic reasons, chose not to act on the warnings.
He says the US goal is "world hegemony, built around securing by force command over the oil supplies" and that this Pax Americana "provides a much better explanation of what actually happened before, during and after 9/11 than the global war on terrorism thesis".
Mr Meacher adds that the US has made "no serious attempt" to catch the al-Qaida leader, Osama bin Laden.
He also criticizes the British government, claiming it is motivated, as is the US, by a desire for oil.
The US government last night expressed abhorrence at Mr Meacher's views. An embassy spokesman in London said: "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.
"My nation remains grateful for the steadfast friendship of the British people and Her Majesty's government as we face, together, the serious challenges that have arisen since September 11 2001."
Downing Street also distanced itself from the views of an MP who only a few months ago was in the government. "The prime minister has responded to those who argue it was about oil," a spokeswoman said, adding that oil profits from Iraq are to be fed back into the country's development.
Former ministers such as Robin Cook and Clare Short have criticized the British government for misleading the public over the reasons for going to war. But Mr Meacher has gone much further in his analysis of US and British motives.
He says that the plans of the neo-conservatives in Washington for action against Afghanistan and Iraq were well in hand before September 11. He questions why the US failed to heed intelligence about al-Qaida operatives in the US and the apparent slow reaction of the US authorities on the day, as well as the subsequent inability to lay hands on Bin Laden.
He argues that the explanation makes sense when seen against the background of the neo-conservative plan.
"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 adds: "Given this, it is not surprising that some have seen the US failure to avert the 9/11 attacks as creating an invaluable pretext for attacking Afghanistan in a war that had clearly already been well planned in advance."
Mr Meacher, who was environment minister, says: "The overriding motivation for this political smokescreen is that the US and the UK are beginning to run out of secure hydrocarbon energy supplies."
He is critical of Britain for allegedly colluding in propagating the myth of a global war of terrorism. He asks: "Is collusion in this myth and junior participation in this project really a proper aspiration for British foreign policy?"
© Guardian Newspapers Limited 2003