The Chancellor will deploy his Budget-day bravura to transform the electoral landscape

He will want to ensure that Labour MPs are saying, 'Could you imagine Alan Milburn doing that?'

The pace is already frantic, yet the race has hardly started. Both parties shot away from the starting blocks as if they were running in the hundred yards. It remains to be seen how they will keep up their speed over the next seven and a half weeks: a marathon by British electoral standards.

Labour is often accused of refighting previous elections. Last week, I ran into a couple of Labour supporters who told me that the party should republish one of its 1997 theme tunes: "Things Can Only Get Better'', in order to reassure Labour activists who have been alarmed by their campaign team's performance. The past few weeks have gone badly for Labour. For once, Mr Blair has not been able to control the political agenda. Unused to being on the defensive, the Blairites become rattled when they find themselves pinned down, as witness John Reid's performance against Jeremy Paxman.

It ought to be a point in Dr Reid's favour that self-pity does not come easily to him. When he tried it, he sounded awful. It was absurd of him to take umbrage at being described as an attack dog. That is precisely what he is, and he is usually good at it. But once a rottweiler loses a dogfight, there is no point in its pretending to be a petulant poodle.

Despite Dr Reid's normal skills, the Government might be advised to put the dogs back in their kennels. Though John Reid is a more likeable and thoughtful man than he usually appears, no one could say the same about Charles Clarke or Peter Hain. They economise on charm. They radiate neither warmth nor reassurance. They do not give the impression of finding it easy to like people, and the voters reciprocate.

The late Gordon Reece, a public relations expert who really understood public opinion, had a dictum: the importance of niceness. "Most TV viewers do not follow political arguments in detail,'' he would say. "But they always ask themselves one question: 'Is this a nice person or a nasty person who has come into my living room?' If the answer is 'a nasty one', then it doesn't matter how powerful a debater the politician is. He will have put them off.''

Recently, Messrs Clarke, Hain and Reid have been doing a lot of that. But a new figure is about to move centre-stage, with the intention of transforming the electoral landscape. In the weekend press, there was a noteworthy aspect to the coverage or Wednesday's Budget: it was so brief.

Over the past eight years, Gordon Brown's spin doctors have shamelessly broken the old rules about Budget secrecy. It used to be ordained that all those involved with the Budget should go into purdah and avoid journalists at even the most innocent of social gatherings. That would never do for New Labour. They wanted advance credit for Budget benefactions, so they leaked them in the way that they also leak populist awards from the honours list.

So this year's silence is interesting. Gordon Brown has decided to keep up the suspense, in order to make Budget day as exciting as possible. His objective is easy to define. He wants to shaft Alan Milburn without destabilising the British economy.

Most economic commentators do not think that the Chancellor has much room for manoeuvre, and that if he is to placate his on/off girlfriend Prudence, this is a year for fiscal restraint. But even a Budget which has little effect on the fiscal balance can be made to scintillate, especially by a Chancellor who is on top of the detail and has an election to win. We can expect a sparkling array of boasts and promises, with billions for popular causes. On closer examination, it will turn out that almost all of those billions had been announced at least once before; Mr Brown is good at that. But before he sits down, he will want to ensure that Labour MPs are saying to one another: "Could you imagine Alan Milburn doing that?''

Gordon Brown and his team believe that the Budget could prove to be the restart button on this election campaign. They have already drafted the passage for the official history of the 2005 election. "After a stuttering start, due to the inept management of Alan Milburn, Tony Blair's choice as election supremo, who did not prove up to the job, the Labour campaign was effectively relaunched by Gordon Brown.''

The Tories are also aware of the Budget's importance. The Shadow Chancellor, Oliver Letwin, has been in briefing meetings night and day, trying to anticipate the Chancellor's tactics. Someone who has observed the process said that it was a bit like hunting the Bismarck. Tiny pieces of information are pored over, to try to create a general picture and predict the battleship's course. The Tories are hoping that Mr Letwin will be as successful. Much depends on this week's contests.

But there is an even bigger question than the Budget. What are the public making of all this? Although everyone in politics seizes on anecdotes, especially when favourable to their party, there is little hard evidence. I wonder what proportion of the electorate has yet decided a) that it will vote and b) how. I would be surprised if the figure were over 40 per cent, and it might be as low as a third. There is a lot of uncertainty, disillusion and scepticism. There are a lot of voters who could still be wooed, or alienated, by some dramatic event.

The Tories are pleased with their performance so far, and rightly. But there is a problem, which the party's strategists identified from the outset. The Tories believe that a lot of people have come to distrust Mr Blair, without being persuaded that there is an alternative. The Tories are convinced that the only way to remedy this is to be positive. The trouble is, however, that it is difficult to preserve a positive campaign amid all the inevitable yah-booery of campaigning. If the voters switch on their televisions and think that they are listening to feeding time at an ill-run dog's home, then - Gordon Reece's point - they will not analyse the programme to discover who is responsible. They will merely feel like sending off all the players.

That is what the Liberals will be hoping. Charles Kennedy will be ready with endless high-minded pietudes about how terrible it is that politicians behave in this way when there are so many vital issues to discuss. The Liberals are normally quick to demand that they should receive more coverage. This time, they have been content to remain in the background, hoping that the voters' distaste for the slagging match will grow.

The Tories will have to find a way of countering this, and of introducing a brief word into their election themes: hope. The dramatic reversals of electoral fortune in British history - 1945, 1964, 1979, 1997 - were all accompanied by a widespread outbreak of hope among the voters. It is difficult for Michael Howard to equal that, which is why it will be so hard for him to reach Downing Street. But if the Tories can find a way of projecting a hopeful message while also discrediting Mr Brown's Budget claims, Labour will be under more pressure than it expected.