With friends like these...

IT'S never exactly been a marriage of equals, but Tony Blair's relationship with George Bush is beginning to look distinctly one-sided. First, the Prime Minister allows himself to be 'persuaded' by the case for invading Iraq, putting both his popularity and his place in history on the line for the sake of keeping in with the President.

Now, it seems he is to be bounced into holding an inquiry into why the Government believed Saddam's arsenal was bristling with chemical and biological weapons, when ten months of searches have not turned up so much as a packet of itching powder.

It was in September 2002, in the foreword to a Government dossier setting out the extent of Saddam's weapons of mass destruction, that Blair wrote of the "serious and current" threat posed by the former Iraqi dictator. He was later to tell the Commons that this WMD programme was "active, detailed and growing," and that these weapons could be activated in 45 minutes.

But now it turns out that this does not appear to have been true. No evidence of WMD has been forthcoming, and a succession of past believers have come forward to renounce their faith.

Last week, David Kay, the former chief US weapons inspector in Iraq, told a Senate committee that he now believed Saddam had no WMD at all. "We were almost all wrong," he told the committee. Then Condoleeza Rice, Bush's national security advisor and one of the President's most trusted aides, admitted that pre-war intelligence on WMD did not tally with what was found on the ground.

But still our Government refused to hold an inquiry into how it could have been so convinced that these WMD were in existence, that it was prepared to sacrifice lives in order to avert the danger. Even on Sunday Peter Hain, Leader of the Commons and one of Blair's loyal lieutenants, was despatched to the television studios to insist that there was "categoric evidence" that Saddam had chemical and biological weapons, and that there was no need for an inquiry.

BUT then Bush threw his curveball, when it emerged he was to set up an inquiry into the intelligence on WMD which was used to justify the war. The President himself has come under considerable pressure to hold such an inquiry, even though the issue of WMD was not his defining reason for going to war, and polls suggest it is not seen as crucial by the American public.

But for Blair, who used the threat posed by Saddam through his WMD as the sole justification for invading Iraq, and who faces a public far more sceptical of the case for war, it makes the case for an inquiry in this country pretty much unanswerable, and the results of such a process assume a far greater importance. He may have hoped that the Hutton Inquiry would satisfy the public appetite for delving into the build-up to the war, but the exclusion of these issues from Hutton's remit, and the backlash against the report's perceived flaws, have ensured it will not be so easy.

"Bush has dropped him in it really, and this shows the Anglo-American relationship working to a British prime minister's disadvantage," says Dr Nick Randall, lecturer in politics at Newcastle University. "There are still a lot of concerns about the decisions that ended up taking Britain into war, and the Bush inquiry is a catalyst for looking at those. There is an enormous question about the way we conduct these defence and foreign policy decisions."

As well as causing more embarrassment for the Prime Minister, an inquiry will also ensure that the Government's second term will be overshadowed by the fall-out from the Iraq war in a way which can only damage its attempt to get across its message in other areas.

Already, the Government has been forced to back-pedal several times, from WMD which could be launched in 45 minutes and posed a threat to mainland Europe, to WMD which could only threaten troops in Iraq, to programmes for the development of WMD. But even these are frustratingly elusive.

And in his desperation to cling on to any sign of WMD, Blair even had the humiliation of being slapped down by Bush's man in Iraq. In his Christmas message to British soldiers in the Gulf, the Prime Minister said there was "massive evidence of a huge system of clandestine laboratories", showing Saddam had attempted to conceal weapons, only for Paul Bremer, head of the Coalition Provisional Authority in Iraq, to dismiss the claim.

According to his aides, the Prime Minister now believes there is a "growing need for an explanation" as to why WMD have not been found, and in an appearance before a committee of backbench MPs today, he is likely to soften his line still further. It is all a far cry from the days when he was convinced of the threat posed by Saddam.

THE British intelligence services were not the only ones to be believe Iraq had a formidable array of weapons. The other partners in the "coalition of the willing", America and Australia, were also misled by the information provided by their experts, or at least their interpretation of it. Even Germany, which opposed the war, believed Saddam had WMD.

But blaming MI6 may not protect the Prime Minister's reputation, according to Dr Randall. "Other institutions may well have provided him with faulty information, but ultimately Blair is going to have to hold his hands up and say 'I was wrong'.

"Whether that is going to be a resigning issue, I suspect not, and I don't think anyone is going to be able to prove that Blair lied, which would be the ultimate sin. But it might be that this generates a lot of disaffection among the public, at a time when Blair might be going for re-election.

"Robin Cook said that if it was all about weapons of mass destruction, why didn't we let the inspectors find them, why did we have to go to war for them? People have lost their lives over this decision and it is the most fundamental decision a prime minister can make. If this was a mistake, it was a bloody big one, and the consequences are a lot more serious than for most government decisions. I don't think an apology will suffice."

Blair may have thought the Hutton Inquiry got him out of the woods, but it's a long way from over yet, and it seems he can't even turn to his friend across the Atlantic for help. The US inquiry is unlikely to report back before the end of the year, so any criticism will conveniently come after the presidential election in November. That may be good news for President Bush, but for a Prime Minister looking to go for re-election next May or June, that could turn out to be very bad timing indeed.