This will be Cameron's finest hour or the scene of a lynching

Fraser Nelson says that the stakes in Blackpool could not be higher: some delegates will actually come in the hope of seeing their beleaguered leader 'take a kicking'. But Cameron is at his best when the chips are down and he has a plan Just six weeks ago, David Cameron was enthusing to friends about Arnold Schwarzenegger's speech to the Conservative party conference. The governor of California had been on the phone, saying how much he was looking forward to visiting Blackpool. It turned out that Schwarzenegger knew what he was in for, having toured England's seaside towns during the bodybuilding pageants of his youth. Then, a fortnight later, he had mysteriously become too busy, and the supposedly relished visit was — well — terminated.

It is a fair bet that a British opinion poll found its way to Sacramento. When Mr Cameron first wrote to the governor, the Tories were ten points ahead. Now — according to a YouGov poll published on Tuesday — he is 11 points behind: and the word is that the notoriously image-conscious Mr Schwarzenegger did not want to grandstand on the deck of a sinking ship. According to one of Arnie's advisers, 'There's just no way he wants to do this particular show any more. He's an image man, and Cameron's image is in the can.' Ditto Rudy Giuliani, the Republican presidential frontrunner, who insisted he was not photographed with Mr Cameron when they met last week. In the pitiless eyes of such figures, the Tory leader's stardust has been replaced by the aura of a loser.

All this makes a murderous backdrop for what will be Mr Cameron's second, and possibly last, conference as Tory party leader. He was the future, once. Now we are in the extraordinary position where serious Tories talk about Mr Cameron being gone by Christmas, after losing an autumn election — and ask whether the Tory party would survive in its current form, or be tom apart by a modernisers-versus-traditionalists war. It is not much of an exaggeration to say that, if Mr Cameron fails, the party may face an existential crisis.

Make no mistake: this is precisely Gordon Brown's goal. He may not have mentioned Mr Cameron by name in his conference speech in Bournemouth this week, but the Tories dominate the discussions, strategy and ambitions of his inner circle. In private conversation, Cabinet members talk incessantly about how their policies will shaft the Tories. Mr Brown will judge the success of his own conference only at the end of the Tory gathering.

One Labour insider explained the thinking to me in Bournemouth earlier this week. 'If Blair had lost in 1997, it would have been the end of Labour as we knew it. We want this to be the end for the Tories. The talk about an early election is a gamble for us: if it focuses their minds, they may unify. But my money is on them thinking they have already lost, and starting to kick each other to death.' It is imperative, in Gordon Brown's election plan, that this killing spree starts now.

As if on cue, a phalanx of senior Tories are quietly preparing themselves for the ritual slaying of yet another leader — a depressingly familiar drama which, as it happens, has a habit of playing itself out before an Olympic year. The party has members aplenty who have long despised Mr Cameron and tolerated him only because he delivered an opinion poll lead over Labour not seen since it was led by Neil Kinnock. One party agent told me that twice the number of people are coming to Blackpool from her constituency — not to prepare for battle against Labour, but, astonishingly, 'because they hate Cameron and want to see him take a kicking'. They come with the same macabre curiosity that led mediaeval villagers to a hanging.

And there will be no shortage of entertainment. Graham Brady, the grammar schools rebel, will return to his subject at a fringe event on Tuesday, likely to be a rallying-point for anti-Cameron feeling. We can expect to hear plenty from Zac Goldsmith, who may be unable to contain his irritation that so much of his environmental policy review, published last week, has already been trashed. 'He has no political experience and a big mouth, so we can expect him to sound off,' says one shadow Cabinet member. 'The rest of us will have to show iron discipline.'

Strikingly, David Davis has pulled out of all his fringe meetings. It is as if the shadow home secretary knows that his every word and aside would have been scrutinised for mischief, and turned into potentially misleading headlines. William Hague (increasingly tipped as a potential successor to Mr Cameron) has pledged to throw the disgruntled activists some red meat by turning up the volume of his calls for a referendum on the EU Treaty. But, as he knows better than most, controlling a Tory conference that does not want to be tamed is an impossible task. It is a wild beast, which can only be sedated by an opinion poll lead.

Unfortunately, the Blackpool conference has been structured in a way that maximises the potential for bedlam. Mr Cameron's speech will be the final fixture of the week on Wednesday afternoon, thus ensuring a four-day escalation of tension where expectations may rise to a stratospheric level. Mr Brown delivered his speech on Monday, and confined his colleagues to a humbling seven minutes each, thus taking the fizz out of the conference instantly. So everything is riding on Mr Cameron's speech.

George Osborne, his shadow chancellor, sets out what is needed in his interview with me on page 18 — from the fog of the policy reviews, a clear policy strategy must now emerge. He is not alone in this analysis. 'David must provide that "click" moment,' says another shadow Cabinet member. 'To govern is to choose. And he must now choose his policies.' The charge of haziness is becoming more potent with each passing month. And — to be fair — this is to be addressed.

The plan in Conservative headquarters is to launch the new Tory vision with much greater clarity through a series of keynote interviews delivered with Cameron, Osborne and Davis in the course of the conference. 'Some proposals from the policy reviews will be explicitly rejected, others explicitly accepted,' says a senior Cameroon. 'He'll say he promised to change the party, that he has and now it's time to deliver. It's time to draw clear dividing lines with Labour.' The aim will be to portray Mr Brown as a Labour leader touting failed ideas, not the father of the nation who is above party politics.

Of all the policy reviews, the most influential has been lain Duncan Smith's 'broken society' inquiry which is to be discussed on two of the four days in the conference. The former leader himself has been unexpectedly asked to speak, an indication of how his work — a true labour of love — has moved to the very heart of his party's strategy and message.

Meanwhile, the wackier ideas to emerge from the other policy groups will be junked, among them Mr Goldsmith's proposal for a 'Happy Planet Index'. His many critics argue that this sort of idea seems to have been hatched on Mars (and it's likely to remain on Mars', says Mr Osborne). Yet environmentalism will not lose its totemic importance in the Cameron project. Greenery remains central to the party's plans as a means of saying 'we've changed' — although this necessarily means green taxes. The conundrum is how to go ahead with this without taxing the less affluent out of the sky.

'Balance' is the new buzz word. Steve Hilton, Mr Cameron's chief strategist, has chosen four key themes: health, environment, the broken society and crime. Yet how far he or anyone else can dictate the agenda is another matter. On page 16, Lord Tebbit sets out a very different plan, focusing on immigration, multiculturalism and English votes for English laws.

There is widespread fear that Mr Brown will have an unpleasant surprise waiting for the Tories on Sunday. 'He's bound to have some defectors lined up,' says one shadow Cabinet member, 'Even if they're a group of councillors from Auchtermuchty. But you can guarantee he'll have held something back for us.'

However, I understand that there will be no such announcements. The Prime Minister has indeed been talking to other Tories interested in 'advising' him in the same way as John Bercow and Patrick Mercer have naively agreed to do. But — crucially — talk of an early election has stalled these discussions. The Tories in question told the Prime Minister's staff that to carry on such talks during a period of election fever was politically impossible.

Labour will instead spend this weekend running opinion polls in marginal constituencies. There is much paranoia in No. 10 about the work of Lord Ashcroft, the Tory's billionaire deputy chairman, who has an office inside Conservative head office and is considered by many to be the de facto party chairman (Caroline Spelman, who holds the position, is widely regarded as a frontwoman). The strategy is simple: his lordship personally donates up to £30,000 to help a candidate fight a particular marginal, knowing that in aggregate these seats will decide the election. Mr Brown cannot consider himself fully informed about his election chances until he polls in these constituencies. It is an expensive exercise, which he would not be undertaking if he wasn't actively considering an election next month.

The Tories are by no means fully prepared for an early election, having yet to select candidates for about a third of the 650 constituencies. But an emergency manifesto has been produced by Oliver Letwin. Lord Ashcroft's Target Seat campaign has already ensured the marginals have both candidates and money. Labour, too, has not found candidates for its more hopeless seats: neither Mr Cameron in Witney nor Mr Osborne in Tatton has a Labour opponent.

If the election does come early, and Mr Cameron does quit after losing, then the growing number of Tories who actively discuss such contingencies describe Lord Ashcroft as the key figure. He is expected to play Bank of England to the Tory party's Northern Rock, acting as guarantor of last resort. He is expected to urge Mr Hague to come back as a unity candidate. But I have still met no one who believes that the shadow foreign secretary — still bringing the house down in his £15,000-a-night speeches — would want his old job again.

Those who see Mr Cameron in private say he is holding up mysteriously well, showing few signs of strain (although those who saw him speak at the Carlton Club on Tuesday evening said he looked gaunt on that particular evening). Unflappability under pressure is his great strength, but can also give an impression of fey indifference. His must balance a new sense of urgency without conveying panic. On the one hand, he needs a 1.5 per cent swing to deprive Mr Brown of his majority. On the other, no opposition party has recovered from being 11 points behind in the polls this far into the political cycle.

But while there is certainly potential for unalloyed disaster at the Winter Gardens, there is also scope for success. The media, frustrated by the mind-numbing dullness of the Labour conference — all glassy eyes and `fresh starts' — might well warm to a 'Comeback Cameron' story rather than fanning the flames of civil war. And like Tony Blair, Mr Cameron is at his best when forced to dance on the precipice. This is perhaps why so many of his colleagues have so much faith that his speech this year will deliver the goods.

It did, after all, do the trick in 2005. After his conference speech two years ago, Mr Cameron held a private drinks reception in the Imperial Hotel in Blackpool. 'I think this has been the start of something,' he said. Many people will gather to the Winter Gardens because they believe this to be the end of something: him It may be cruel and unfair, but most people in Westminster believe the election to be lost already, and Mr Cameron to have already failed. He has until 3 p.m. on Wednesday to prove them all wrong.