Now we know just how far Parliament was misled over Iraq

Tony Blair cannot hope to draw a line under this miserable episode without answering the questions Hutton will leave behind

On Monday Parliament gets back to business. This itself is a novelty, as it is the first scheduled sitting in September to which any of the present members of Parliament have been summoned. September sittings were included in the modernisation package because it cannot be healthy for Parliament to disappear for three long months leaving no representative forum which could hold ministers to account. I remember a warning at the time that every year events took place in our absence which Parliament must debate if it was not to sink into irrelevance. I freely admit that I never foresaw an event as riveting and as revealing as the Hutton inquiry.

Lord Hutton has done more in six weeks to advance the cause of freedom of information than this Labour government has done in six years. In the process he has demolished the case which the Government made for war. Some commentators have deplored the restriction of Hutton's remit to the death of Dr Kelly, but I welcome the consequence that the rest of us are free to draw our own conclusions from the other evidence he has unearthed. Number 10 cannot tell Parliament next week to sit quietly and wait on the findings of the inquiry when we all know that it has ordered Lord Hutton not to come to any findings on the case for war.

But the Hutton inquiry has given Parliament plenty of leads to pursue. Why did the Prime Minister try to persuade MPs that Saddam was "a current and serious threat'' when we now know that Tony Blair could not convince his own chief of staff, Jonathan Powell, that Saddam was an imminent threat. Even Alastair Campbell, Tony's alter ego, appears to have had his doubts. In his diary, the month the dossier is published, he asks, "Why was this such an important issue to the British government now? Why Iraq? Why only Iraq?"

Then there is yesterday's revelation that members of the Defence Intelligence Staff did not agree with the case that defence ministers were making to Parliament. We now know that Britain's leading expert on chemical weapons regarded the September dossier as too much the work of "spin merchants''. Breathtakingly, we have also discovered that the allegedly "reliable'' source for the 45-minute claim did not appear to know very much about what he was talking about.

The Government has built its defence on the claim that everything in the September dossier was approved by the Joint Intelligence Committee. That basis looks a lot more wobbly today, since we have learnt that the Committee only managed to approve the dossier as published by rejecting six pages of detailed criticism of it from intelligence officials.

Having allowed itself to be misled once over whether Saddam posed a current threat, Parliament must not allow itself to be misled a second time into accepting the Government's argument that the real issue is whether one BBC interview (at seven minutes past six in the morning!) was wrong. Tony Blair told Hutton that this interview was so damaging it brought into question "the credibility of the whole country''. I wish to be loyal to my Prime Minister and I have tried hard to swallow this claim, but I discovered it always sticks in my gullet. From my contacts with European and Arab friends, I know that what has seriously damaged the credibility of my country is that its government launched a war, in which at least 10,000 were killed, on a false prospectus.

That is the real issue. There are no weapons of mass destruction. There was no contract for uranium from Niger. There never were any chemical weapon plants rebuilt by Saddam. The gulf between the rhetoric before the war of Blair and Bush and the reality on the ground after the war has turned out to be so spectacularly wide that now we learn that the intelligence communities on both sides of the Atlantic have launched an investigation as to whether they were duped by Iraqi defectors.

Stripped of its high moral tone, the bones of Tony Blair's defence is that he may have turned out to be wrong, but at the time he believed he was right. But this does not explain why he believed he was right. The rings of e-mail unearthed by Hutton are peppered with laments that the intelligence is thin and the evidence not convincing enough. In a rational, sane environment, any Prime Minister should have asked himself whether the intelligence could be misleading. Tony Blair did not ask that question because he wanted to believe the intelligence was right.

And they so wanted the rest of Britain also to believe in the threat. No doubt it is true that the Joint Intelligence Committee gave its holy imprimatur to every claim in the dossier, but if so they were persuaded to sign up to some rather bold half-truths. Take the notorious claim that Saddam had weapons of mass destruction ready to be fired in 45 minutes. Thanks to Hutton we now know that John Scarlett never believed this claim applied to real weapons of mass destruction, but to battlefield shells and "small-calibre weaponry''. That was not the impression created by the dossier, which was crafted by people who knew only too well that Parliament would not vote for war because Saddam had small-calibre weapons ready for use in 45 minutes.

Even ministers have given up pretending that they now expect to find actual weapons. Instead they have spent the past two months lowering expectations by encouraging the public to settle for evidence of programmes of weapons of mass destruction as proof that the dossier was right all along. Yet Hutton has now blocked even this bolthole.

Of all the embarrassing evidence released by the Hutton inquiry, I found most damning the discovery that until a week before publication the title of the dossier was Iraq's Programmes of Weapons of Mass Destruction. The decision to drop "Programmes'' from the title was deliberately calculated to encourage the belief that Iraq already had weapons and the threat therefore was urgent. Ministers cannot now ask Parliament to accept a justification for war based on evidence of programmes, when they themselves have been caught out rejecting that as the basis on which they asked Parliament to vote for war.

Since Tony Blair's appearance before Hutton, the press have been briefed that at the Labour conference he will cut back on his international priorities and focus on the domestic agenda. Labour activists will greet such a development with a welcoming cheer. Most of them deplore the loss of a year in government as a result of his insistence on the adventure in Iraq. But Tony Blair cannot hope to draw a line under the whole miserable episode without answering the central questions that Hutton will leave behind.

Why did government statements exaggerate the threat from Saddam? Why was the need for invasion so urgent that he could not wait on the UN weapons inspectors finishing the job? And how does he halt the deteriorating security situation in the Iraq we claim to have liberated?