E-mail traffic reveals the frenzied atmosphere of a mole hunt

The Hutton inquiry has lifted the lid on the workings of modern government in general and Tony Blair's "top down" system of governing in particular. Whatever conclusion Lord Hutton reaches on the death of David Kelly, his investigation has performed a valuable service by shining a spotlight on the inner workings of the Blair Government.

It is not a pretty picture. The flurry of e-mails, letters and memos captures an increasingly feverish atmosphere as the government machine tries desperately to find the source of the BBC's allegations that its Iraq dossier was "sexed up".

Some observers are surprised that so many e-mails are winging their way round Whitehall when the practice should have been discouraged by the notorious message sent by Jo Moore, the special adviser who said 11 September 2001 would be a good day to bury bad news. After that many officials vowed never to put anything sensitive in writing.

Yet the intense pressure of government suggests that people are still sending messages they may regret. The classic example is the e-mail by Tom Kelly, Tony Blair's official spokesman, to his chief of staff Jonathan Powell, saying: "This now a game of chicken with the Beeb -- the only way they will shift is [if] they see the screw tightening." The Downing Street spokesman's phrase unwittingly symbolises the emerging picture of how David Kelly was caught in the crossfire between the Government and the BBC. It may well shape Lord Hutton's findings.

The documents are also threatening to undermine Downing Street's strategy of keeping distance between Number 10 and the handling of Dr Kelly. Downing Street has repeatedly stressed that the Ministry of Defence was the "lead department" in dealing with essentially a "personnel matter." But the Whitehall traffic shows how Mr Blair took a very close interest in the affair. Further trails leading to his door are bound to emerge.

At one level, it is no surprise that Downing Street was closely involved. Mr Blair came to power determined that Number 10's writ should run throughout Whitehall and has set up a Prime Minister's Department in all but name. Unfortunately for Mr Blair, he cannot have it both ways, running a centralised machine when it suits him and then washing his hands when things go wrong.

The latest batch of documents reinforce how a supposedly neutral Civil Service was dragged into Alastair Campbell's gladiatorial struggle with the BBC journalist Andrew Gilligan. Sir Kevin Tebbit, the MoD's permanent secretary, told colleagues in one letter that the issue of what David Kelly told Mr Gilligan "must be pinned down as clearly is possible because of the continuing problem with the BBC".

Another exchange of e-mails inside Downing Street reveals moves to use Parliament's Intelligence and Security Committee (ISC) as a weapon in the battle with Mr Gilligan.

Mr Campbell told colleagues: "If the BBC source situation develops as it might, surely it is in our interest for the ISC to delve deeply into this, by interviewing the source and Gilligan and myself."

Mr Powell replied to Mr Campbell: "We should certainly get them to interview Gilligan and source, best if you give evidence after both of them."

But the ISC decided not to interview Mr Gilligan; and Sir David Manning, Mr Blair's former foreign adviser, intervened to stop Mr Campbell giving evidence, saying: "ISC should concentrate on intelligence issues, talking to heads of agencies and chairman of JIC."

Another note from Mr Powell says Mr Blair should not overstate Iraq's threat in the dossier. He wrote: "In the penultimate para you need to make it clear Saddam could not attack us at the moment. The thesis is he would be a threat to the UK in the future if we do not check him." His advice was ignored.