Michael Brown: Cameron needs to hold his nerve – or defeat will loom

What seemed a certain victory last autumn now looks like a struggle

When the Tories met in Manchester last October for their final party conference before the election, the scent of a glorious victory was in the nostrils of most parliamentary candidates. By contrast, as the Tory party gathers tonight in Brighton for its final weekend rally before the election, far from being triumphant, the mood will be distinctly sober, queasy and nervous.

Candidates who have been slogging it out in the marginals for the past four years will be jealous of their Cameroon "A-list gold card" counter-parts who have slipped effortlessly into safe seats, only weeks before polling day, vacated in the wake of the expenses scandal. Many of the latter have never previously stood for Parliament and some have only recently joined the Tory Party.

On Sunday, David Cameron will strike a rhetorical note and call upon his troops to go back to their constituencies and prepare for government. But what seemed a certain victory last autumn now looks like a struggle. With Labour closing the gap, in spite of Gordon Brown's tears and tantrums it must be frustrating for the Tories to see their poll lead melt. Polling evidence suggests that the Prime Minister might actually be benefiting because of his crying and bullying.

But notwithstanding a sense of panic in the ranks, Mr Cameron still has hidden advantages that may yet secure a comfortable Commons majority. According to this week's PR/Angus Reid poll in Labour marginals (where Tories are the main challengers) there is a 12 per cent swing from Labour to the Tories since the 2005 election compared with the 7.5 per cent swing registered in the national polls. Private polling for the Tories also seems to indicate that they are making their votes count where it matters.

So Mr Cameron, who under pressure is more than capable of keeping a cool head, should not succumb to the growing panic now beginning to overtake sections of the incumbents in the parliamentary party. But he does need to convey a sense that, even though we (including me) do not always know what he stands for, he at least knows his own mind.

Watching friends fight hard to gain seats, I am re-living my own experiences of the run-up to 1979. But they find it difficult, however, to parrot the conflicting messages that appear from the leadership at different times. I console them by saying that even though I did not know always know what was in Margaret Thatcher's mind I was able to convey to doubtful voters a sense that she certainly knew her own mind. Hence I was able to convince voters that taxes would eventually be lower without knowing beforehand the extent of the spending cuts and VAT increases that would follow a Tory victory.

This should be the weekend when Mr Cameron's instincts should rule, and when he leaves behind his head's obsession with the focus groups. A greater reliance on the wily Kenneth Clarke rather than the coterie of munchkins led by Steve Hilton – inclined to practise voodoo politics – might not go amiss. George Osborne's impressive Mais lecture suggests, thankfully, that we may be back to the Tory message of "austerity" which he bravely began to set out last autumn. When the hocus pocus of the focus groups suggested this was too pessimistic the leadership has appeared to lose its nerve.

If anyone stands between Mr Cameron and a decisive victory it is probably Alistair Darling who, by one unintended slip of the tongue on TV, has suddenly been compared to Roy Jenkins as a good post-war Chancellor. With nothing to lose, given that whatever the outcome of the election the removal van will certainly be arriving at Number 11, the Chancellor, being an honest politician, is at least determined to maintain his deserved personal reputation as an honourable public servant. He has the political space and credibility to introduce the Budget in three weeks' time that will shape the next two years of either government to a greater extent than anything brought forward by Mr Osborne a few weeks later.

If any cuts proposed by the Chancellor are precise, detailed and plausibly painful, will the Tories lay out publicly even more cuts before the election? If they can answer that question my bet on a Cameron majority of 30 still stands – although I never under-estimate the ability of the Tory Party to snatch defeat from the jaws of victory.