Revealed: How the road to war was paved with lies

Intelligence agencies accuse Bush and Blair of distorting and fabricating evidence in rush to war

The case for invading Iraq to remove its weapons of mass destruction was based on selective use of intelligence, exaggeration, use of sources known to be discredited and outright fabrication, The Independent on Sunday can reveal.

A high-level UK source said last night that intelligence agencies on both sides of the Atlantic were furious that briefings they gave political leaders were distorted in the rush to war with Iraq. "They ignored intelligence assessments which said Iraq was not a threat," the source said. Quoting an editorial in a Middle East newspaper which said, "Washington has to prove its case. If it does not, the world will for ever believe that it paved the road to war with lies", he added: "You can draw your own conclusions."

UN inspectors who left Iraq just before the war started were searching for four categories of weapons: nuclear, chemical, biological and missiles capable of flying beyond a range of 93 miles. They found ample evidence that Iraq was not co-operating, but none to support British and American assertions that Saddam Hussein's regime posed an imminent threat to the world.

On nuclear weapons, the British Government claimed that the former regime sought uranium feed material from the government of Niger in west Africa. This was based on letters later described by the International Atomic Energy Agency as crude forgeries.

On chemical weapons, a CIA report on the likelihood that Saddam would use weapons of mass destruction was partially declassified. The parts released were those which made it appear that the danger was high; only after pressure from Senator Bob Graham, head of the Senate Intelligence Committee, was the whole report declassified, including the conclusion that the chances of Iraq using chemical weapons were "very low" for the "foreseeable future".

On biological weapons, the US Secretary of State, Colin Powell, told the UN Security Council in February that the former regime had up to 18 mobile laboratories. He attributed the information to "defectors" from Iraq, without saying that their claims – including one of a "secret biological laboratory beneath the Saddam Hussein hospital in central Baghdad" – had repeatedly been disproved by UN weapons inspectors.

On missiles, Iraq accepted UN demands to destroy its al-Samoud weapons, despite disputing claims that they exceeded the permitted range. No banned Scud missiles were found before or since, but last week the Secretary of State for Defence, Geoff Hoon, suggested Scuds had been fired during the war. There is no proof any were in fact Scuds.

Some American officials have all but conceded that the weapons of mass destruction campaign was simply a means to an end – a "global show of American power and democracy", as ABC News in the US put it. "We were not lying," it was told by one official. "But it was just a matter of emphasis." American and British teams claim they are scouring Iraq in search of definitive evidence but none has so far been found, even though the sites considered most promising have been searched, and senior figures such as Tariq Aziz, the former Deputy Prime Minister, intelligence chiefs and the man believed to be in charge of Iraq's chemical weapons programme are in custody.

Robin Cook, who as Foreign Secretary would have received high-level security briefings, said last week that "it was difficult to believe that Saddam had the capacity to hit us". Mr Cook resigned from the Government on the eve of war, but was still in the Cabinet as Leader of the House when it released highly contentious dossiers to bolster its case.

One report released last autumn by Tony Blair said that Iraq could deploy chemical and biological weapons within 45 minutes, but last week Mr Hoon said that such weapons might have escaped detection because they had been dismantled and buried. A later Downing Street "intelligence" dossier was shown to have been largely plagiarised from three articles in academic publications. "You cannot just cherry-pick evidence that suits your case and ignore the rest. It is a cardinal rule of intelligence," said one aggrieved officer. "Yet that is what the PM is doing." Another said: "What we have is a few strands of highly circumstantial evidence, and to justify an attack on Iraq it is being presented as a cast-iron case. That really is not good enough."

Glen Rangwala, the Cambridge University analyst who first pointed out Downing Street's plagiarism, said ministers had claimed before the war to have information which could not be disclosed because agents in Iraq would be endangered. "That doesn't apply any more, but they haven't come up with the evidence," he said. "They lack credibility."

Mr Rangwala said much of the information on WMDs had come from Ahmed Chalabi's Iraqi National Congress (INC), which received Pentagon money for intelligence-gathering. "The INC saw the demand, and provided what was needed," he said. "The implication is that they polluted the whole US intelligence effort."

Facing calls for proof of their allegations, senior members of both the US and British governments are suggesting that so-called WMDs were destroyed after the departure of UN inspectors on the eve of war – a possibility raised by President George Bush for the first time on Thursday.

This in itself, however, appears to be an example of what the chief UN weapons inspector Hans Blix called "shaky intelligence". An Iraqi scientist, writing under a pseudonym, said in a note slipped to a driver in a US convoy that he had proof information was kept from the inspectors, and that Iraqi officials had destroyed chemical weapons just before the war.

Other explanations for the failure to find WMDs include the possibility that they might have been smuggled to Syria, or so well hidden that they could take months, even years, to find. But last week it emerged that two of four American mobile teams in Iraq had been switched from looking for WMDs to other tasks, though three new teams from less specialised units were said to have been assigned to the quest for "unconventional weapons" – the less emotive term which is now preferred.

Mr Powell and Mr Bush both repeated last week that Iraq had WMDs. But one official said privately that "in the end, history and the American people will judge the US not by whether its officials found canisters of poison gas or vials of some biological agent [but] by whether this war marked the beginning of the end for the terrorists who hate America".