Anne Penketh: How dare they call him a Walter Mitty fantasist?

It's as if he's being made to pay for what is obvious: the Government magnified the risks of WMD

Even in death, David Kelly cannot rest easy. The Downing Street spin machine has pursued the country's most distinguished germ warfare expert beyond the grave to smear his reputation.

When I read The Independent on Monday, I could scarcely believe my eyes. Here was Dr Kelly now being described by a senior Whitehall source as a "Walter Mitty" fantasist, in an outrageous slur on his character in the very week of his funeral. Whatever next? Before his death, he had already been described as the "MoD mole" and the "leaker", as if he were a whistle-blower with an axe to grind, telephoning journalists to denounce his political masters.

But that is not the David Kelly known to journalists who sought his guidance in the run-up to the war in Iraq. Like other former UN weapons inspectors, he was well placed to set them straight on what was already known about the threat from Iraqi weapons of mass destruction and what was Downing Street spin. Off the record, of course. As his former boss, Rolf Ekeus, told me the other day, the cool and courteous Dr Kelly was "upright" and "honest" and totally "non-political".

Mercifully, Dr Kelly was used to the UN system, which allows its experts to talk to journalists on an anonymous basis in the interests of helping them get to the truth. They would never ring you, but would return your call if they trusted you. And if they trusted you, they talked. Dr Kelly was an expert's expert, as were all the UN weapons inspectors, chosen for their expertise in their fields. In that of biological warfare, he worked with three other eminent specialists, who called themselves the "gang of four" or the "grumpy old men": Richard Spertzel, a US germ warfare specialist, who once worked at Fort Detrick (America's Porton Down); Hamish Killop, from the British military, who specialised in weapons delivery systems; and Rod Barton, an Australian arms control expert.

It may have come as a surprise to Tony Blair, but for anyone who worked in New York in the 1990s covering the UN standoffs with Iraq, not much was new in the Government's documents about the threat from Iraqi weapons of mass destruction. It had almost all been published on the UN website - apart from claims such as the discredited Niger documents and the 45-minute deployment, which were never sufficiently verified to make their way into a UN document. When the now infamous September dossier was published, the weapons inspectors I spoke to told me that the Government's case looked more like an argument for more inspections than a casus belli.

As the Government now admits, the warnings about Iraqi stocks of anthrax, nerve gas and the like, which contributed to building the threat in the September dossier of a "current and serious threat to the UK national interest" were recycled from UN documents dating from 1998. The trouble is that whereas the UN inspectors said that the germ warfare and chemical agents remained "unaccounted for", the Government's version implied that the stockpiles still existed.

Dr Kelly is not the only expert to have expressed doubts about the September dossier. Hans Blix ordered the UN inspectors to prepare their own critique of the UK report. There were "lots of things that we couldn't support", one of them told me last week. He added, however, that the inspectors assumed that the British Government was working from intelligence that was not available to the inspectors...

That is why the unfolding tragedy of the past weeks has seemed even more incredible. It is as though David Kelly was being made to pay for what had seemed obvious to many: that the Government exaggerated the risk posed to Britain's national security in order to wage war on Iraq to depose Saddam Hussein.

Now, after being initially described as a "middle-ranking technician" before it emerged that he was, in fact, the country's foremost expert on biological weapons, Dr Kelly has become a "Walter Mitty". Of course, the Government has apologised, after the usual denials. But how much more rewriting of history will happen before the Hutton inquiry concludes?

There is another chilling aspect to this "story", which strikes to the heart of journalistic enquiry. The Kelly affair has dealt a serious blow to the protection of the anonymity of sources. Why should former weapons inspectors - or others - talk to the press now? What if their much prized anonymity is blown? Ironically, Downing Street has now become the victim of its own game, after journalists, in what looks like a remarkable act of revenge, "outed" a Downing Street spokesman, Tom Kelly, as the source of the "Walter Mitty" comment.

If I could suggest a course of action for the Downing Street spinmeisters, it would be, in the immortal words of John Prescott: "For God's sake, shut up for the summer."

a.penketh@independent.co.uk