Iain Duncan Smith has missed an open goal, but he has one more chance

If the Tories are to put across the message that they are anti-spin, they will need an effective, unseen, spin machine

The Government is unravelling before our eyes. The death of a public servant has led Tony Blair to do three things he never before contemplated. First, after vowing years ago not to get bogged down in a public inquiry over any aspect of his own government, he has been panicked into setting one up. This fateful decision, unavoidable though it probably was, will be seen as the beginning of the end for Mr Blair.

Speaking to the Hutton inquiry yesterday, Janice Kelly blew apart any notion that the Prime Minister, his senior officials or the Ministry of Defence did anything to protect her late husband's identity or to concern themselves with his welfare. This evidence will have a great impact on public opinion, and will surely cost Geoff Hoon and the Downing Street press officer, Tom Kelly, their jobs.

Second, the laying bare by the inquiry hearings of the structures underpinning the Government means that Mr Blair will finally have to face up to the end of Alastair Campbell's reign of terror. And third, Mr Blair has now stumbled across a door inside Number 10 Downing Street marked "Cabinet Room". It is suggested that the Prime Minister believes that all individual cabinet ministers should sit down together with him and arrive at decisions through collective discussions.

But do not be deceived. This government will be incapable of continuing without the structures that it brought with it into office in 1997. Already, Peter Mandelson is talking up his own prospects of resuming Mr Campbell's spin cycle. The hints that there is to be a "Ministry of Truth" are a reminder that, fundamentally, nothing is actually going to change. It was, of course, another Blair - Eric Blair - who, under the pseudonym George Orwell, first conceived of such an institution.

Any attempt to change either gear or style will fail. The events of the past few days suggest that any announcement of a return to a traditional style of cabinet government is merely a continuation of the exercise of spin. The Government is now so distrusted that attempts at a "relaunch" - especially with Mr Mandelson as mastermind - will be thoroughly discounted by the general public. The fact is that once a government even uses the word "relaunch", it is publicly admitting that it has no idea of where it is going. I have forgotten the number of times I was party to discussions in the engine room of the Major government when it came to "relaunches".

For the Conservative Opposition, this is now the opportunity to wake up. And Iain Duncan Smith seems, at last, to be rousing himself from his summer slumbers. He appears to recognise that the hand of history, and the ghost of Dr Kelly, may eventually throttle Mr Blair. It is a shame that the Tories vacated the open goal presented to them during the past four weeks, although I accept that it is a fine line to tread between intruding on the grief of Mrs Kelly and making political capital out of the Government's discomfort. Being a decent man, Mr Duncan Smith understandably did not want to be accused of using the tragedy for his own ends.

But, as the first part of the Hutton inquiry draws to a close tomorrow, the focus will be back on the party political debate, with the House of Commons returning, next week for its first pre-conference session - following the new arrangements put in place by Robin Cook before he resigned as Leader of the House.

How Mr Duncan Smith plays the next few weeks both in Parliament and during the party conference season will be crucial in establishing him - rather than Gordon Brown - as the alternative Prime Minister to Mr Blair. For the past few months, the Opposition's strategy has been ruled by a fear of being in the headlines for the wrong reasons. After the personnel débâcles of the spring, IDS seems to have put the Tory party on a quiet "tick-over" footing.

This may have spared them unfortunate "Tory rows" headlines. But it has also prevented IDS from undertaking the necessary Shadow Cabinet reshuffle, which he ought to contemplate before the new parliamentary session in November. This might now even be the time for quiet chats with William Hague, Francis Maude and - dare I say it - even Ken Clarke and Michael Portillo, to see if they might be willing to play a full part in the next stage of the Tory party's revival.

In his attack on Labour's failed culture of spin, repeated over the weekend in his Independent on Sunday article, IDS has failed to recognise the benefits of enforcing discipline in the ranks, both in Parliament and in Central Office. Alastair Campbell's spin machine, which has turned out to be a disaster after six years in government, was nevertheless a great success for Labour in opposition; if the Tories are to put across to the public and the media the message that they are anti-spin, they themselves will need an effective, albeit unseen and unacknowledged, spin machine.

There have been some suggestions that Mr Duncan Smith has kept his senior troops off the airwaves because he is frightened of unfavourable comparisons between himself and others in the Shadow Cabinet. But if the comparison often made of IDS with Clement Attlee (to which IDS apparently does not object) is to be sustainable, it means allowing his senior lieutenants to go on the media circuit without worrying whether they are after his job.

How he has managed to escape a leadership challenge during the first six months of this year amazes me. But having survived, he should recognise that he has already achieved what seemed impossible. This should give him the confidence to trust his colleagues. David Davis, who always looks good on television, should be used more extensively in broadcasts, while Michael Howard should take every opportunity to respond in parliamentary debates.

Of course, it is not only the trust factor that will ultimately decide the electoral fate of the Government. Gordon Brown's forthcoming decisions on how to deal with the ballooning budget deficit will be both an opportunity and a nightmare for the Opposition. For too long they have fought on Labour's ground on the public services. It is clear, though, that the next election can be brought back on to the Tory agenda of lower taxes.

Up to now, every tax increase has been made with the Tories trapped in the headlights of the charge of "Tory cuts" whenever they have opposed such increases. But they now have a unique opportunity to make the straightforward case against higher public expenditure. The Government has never been more vulnerable to backbench revolts on issues such as foundation hospitals. This means that there is no likelihood of Mr Blair being able to successfully reform the public services without splitting the Labour Party. Labour has provided Iain Duncan Smith with an unmissable open goal. He should wake up and start kicking - hard.

mrbrown@pimlico.freeserve.co.uk