There is one thing Iain Duncan Smith could say to please his party conference

It may still be necessary for Tory MPs who want to change their leader to sharpen their daggers

A week ago, Iain Duncan Smith was one cock-up away from a terminal crisis. Since then, there has been a further deterioration. It has become clear that his standing has been so eroded that he is now only the nominal leader of the Conservative Party. He has forfeited the respect of his colleagues to such an extent that he has lost almost all authority.

There was a brutal demonstration of this at the end of last week, after a rumour swept around that the BBC was about to make allegations of financial impropriety against Mr Duncan Smith. If something like that were to happen in normal circumstances, the Tory party would circle the wagons, especially when dealing with the BBC. Most Tories regard the BBC as an inveterate foe, which would relish any opportunity to make trouble just before a party conference (that may still be the reaction of many Tory activists in the conference hall).

To many Tory MPs, however, the whole thing was a matter for covert rejoicing. Perhaps Mr Duncan Smith might now decide that he has had enough and that it was time to walk away. He nearly resigned around this time last year, because he began to despair at his lack of progress. So the BBC might provide the final push. Instead, it decided to hold its fire; it may still be necessary for Tory MPs who want to change their leader to sharpen their daggers. But if Mr Duncan Smith retained any political judgement, he ought to decide to improve his standing with history and to make the following speech.

"Ladies and gentlemen, two years ago, I became the leader of our party and they have not been wasted years. We have made progress, especially on new policies, which will form a sound basis for a successful electoral programme. Right at the beginning, I made two decisions, which I have adhered to. The first concerned Europe. In recent years, we Tories had often enabled our opponents to caricature us as a single-issue party, a mere Eurosceptic pressure group, which had nothing to say about anything else. I was determined that this should stop. We would, of course, remain resolute in opposition to federalism and in support of the pound. But we would talk about other things as well. We would speak much more about the issues which interested the British people and far less about the ones which obsessed us.

"I was equally determined to ensure that we would use our time productively. If we had to spend another term in opposition, we must turn penance into progress. We should seize the time to re-work our policies, as Margaret Thatcher and Keith Joseph did in the mid-Seventies. Like them, we would open up new intellectual battlegrounds: in our case, the public services.

"We have done all that, with remarkable success in so short a time, and I would like to thank all my colleagues for their efforts. All those who have looked at our new policies have been impressed; all 500 of them, most of whom are in this hall today.

"For we have failed to project our message to a wider audience, because we have a basic difficulty. Me.

"There is a problem with which the England cricket selectors have long been familiar; the batsman who makes lots of runs in county cricket, but cannot raise his game to Test level. I was not a bad shadow minister - I hope William Hague would agree - which helped me to get this job. But as leader I have remained in the shadows. No one seems interested in listening to the quiet man.

"Well, we cannot go on like that; there is an election to win. We are facing a government which is routinely dishonest. You don't have to take my word for that; just read what its leading figures say about one another. We have a government in which the Chancellor is in open revolt. As he told us last week, he wants "Old Labour, new leader''. The PM and the Chancellor are not even on speaking terms, and the voters won't be speaking to them either, when they discover how much their taxes have increased and how much of their money has been squandered. Tony Blair tells us that he has no reverse gear. That may be true - but as long as he is in Downing Street, the whole country is going in reverse.

"Whatever Lord Hutton should say, there is a formidable prosecution indictment to be made against this government for serial gimmickry, serial waste, serial dishonesty, serial betrayal. But the case has to be made. I could not bear the thought of this government spinning its way back to power because I was the wrong prosecuting counsel. Still less could I bear the thought that the Liberals, those most unworthy of opponents, could profit from the Government's difficulties and make further gains at our expense.

"So I am standing aside. I hope that all those involved in organising the leadership election will co-operate to speed up the process, to provide us with a new leader by Christmas. Then we will all combine to roar him home (sorry, Theresa, it will be a him). He will also start with a double advantage. He will be able to use all the policy work which I will leave him. But unlike me, he will be able to persuade the voters that our party has thought about the challenges of government and is now ready to confront them.

''When the new leader wins the next election, I will feel a twinge of envy. It hasn't always been fun, wandering about in the wilderness. Poor Moses: 40 years; sometimes I have begun to understand how he must have felt. Anyway, fellow Conservatives, we have been in the desert of opposition for long enough. It is time for a Joshua to emerge and lead us to the Promised Land.''

If Iain Duncan Smith were to make such a speech, Blackpool would run out of Kleenex, a couple of thousand Tories who had spent the previous 72 hours blackguarding their leader would be embarrassed by how they had been behaving, and there would be an onrush of sympathy which would sweep IDS to heights of popularity that he had never previously known. Unfortunately for him, that is his only hope of reaching them. As he has some oriental blood, it is now time for him to turn Buddhist and recognise that the road of renunciation is the road to redemption.

It is more likely, however, that Mr Duncan Smith will persist in blocking the path between his party and nirvana. If so, the wheel must turn, and fast. It only takes 25 Tory MPs to initiate a leadership challenge, yet at present, it would be hard to find 25 Tory MPs who think that they have the right leader.

Indeed, there is only one way in which IDS could be re-elected as Leader of the Opposition. If Labour and Liberal MPs were entitled to vote, he would be swept to victory by a triumphant margin. No Tory leader has ever been so popular with his political opponents; no Tory party has ever been so unwilling to frustrate its opponents' hopes. IDS is an island of ineptitude in a sea of political opportunity. The Tory parliamentary party must act to put that right, and soon.