Six weeks ago The Sunday Times published the leaked minutes of a July 2002 Downing Street meeting in which Tony Blair committed Britain to war in Iraq months before parliament was consulted.

They detailed a secret pledge to President George W Bush to help oust Saddam, showed that Lord Goldsmith, the attorney-general, had warned such action could be illegal and that Jack Straw, the foreign secretary, had thought the case for war was “thin”.

By any standards these were fascinating revelations. Nothing, however, could have prepared us for what a worldwide impact the story would have. More than a month later it still features in the daily top 10 most popular stories on our website, with 330,000 people estimated to have logged on to read it.

Though it remains unclear to what extent the leaked documents had on the general election (held four days after the story broke), anger about the war is widely seen as the key reason for the government’s severely reduced majority.

What is clearer is that they are having a strong effect on public perception in America, where there has been a wave of interest in the leak. At least two websites, afterdowningstreet.org and downingstreetmemo.com, have been set up to draw public attention to the leaked minutes. The former received more than 1.6m hits on a single day last week (it averages above 1m a day) while the latter has been selling out of T-shirts bearing the legend: “Did you get the Downing Street Memo?” Last week the leaked documents stormed the mainstream US media when they were raised at a White House news conference, forcing Tony Blair and George Bush to address the issue.

The minutes showed that Sir Richard Dearlove, then head of MI6, warned Blair’s war cabinet that “the intelligence and facts were being fixed around the policy”. The prime minister, who had chaired that July meeting, told the White House briefing room that “the facts were not being fixed in any shape at all”.

The American public is not so sure. Last week a Washington Post-ABC News poll found for the first time that a majority of Americans — 52% — felt the war in Iraq had not made the United States safer.

Today we publish further revelations in the news section in the form of a July 2002 Cabinet Office briefing paper.

It makes clear that both Blair and Bush have a lot to apologise for: “When the prime minister discussed Iraq with President Bush at Crawford in April he said that the UK would support military action to bring about regime change,” it states, adding that “regime change per se is illegal”.

As a prime minister had agreed to do something that was illegal under British interpretation of international law, it was “necessary to create the conditions in which we could legally support regime change”, the briefing paper says.

For Blair, “creating the conditions” meant going to the United Nations to get a unanimous resolution warning Iraq to co- operate with the inspectors or else. Bush needed the backing of Congress and he didn’t get that until October 11, 2002.

But as Geoff Hoon, then British defence secretary, said in that Downing Street meeting in July 2002, the “US had already begun ‘spikes of activity’ to put pressure on the regime”.

No bombs were dropped on southern Iraq in March 2002 but by July, with the “spikes of activity” in full flow, about 10 tons of bombs were being dropped a month. The problem was that the Iraqis didn’t retaliate. They didn’t provide the excuse Bush and Blair needed.

So at the end of August the allies started the air war anyway. The number of bombs dropped on southern Iraq shot up to 54.6 tons in September alone.

The authenticity of these figures is not in doubt. They were obtained from the government by parliamentary questions put by the Liberal Democrats so they are up on the Hansard website for all the internet bloggers to see.

They show that Bush and Blair began their war, not in March 2003 as most believed, but at the end of August 2002, six weeks before Bush received his congressional backing, and more than two months before the UN vote.

That is why the wave of public awareness sweeping America is so dangerous to Bush and why he has refused to answer a letter from 89 Democratic congressmen asking if the intelligence was “fixed” and precisely when he and Blair actually agreed to go to war.

John Conyers, the Demo-cratic congressman who drafted the letter, promised when downingstreetmemo.com was set up last week that once 250,000 people had signed the website’s petition demanding the same answers he would deliver it to Bush.

By Friday more than 500,000 people had signed and it seems likely that by next Thursday when Conyers carries the petition up to the White House gates the names on it will number well over a million.

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