Bruce Anderson: Cameron need only tell the truth to overtake Labour - that public spending is too high

Labour has to come up with an alternative, although Gordon Brown thinks this is unnecessary

On a scale of rational expectation from one to 10, David Cameron's first week came out at around 20. This is useful. It enhances both his self-confidence and the esteem of his colleagues, which will carry him through the inevitable bad weeks.

Moreover, the Labour Party is uneasy. A lot of Labour MPs are now realising that they have been under-rating Mr Cameron, because of a silly mistake. Even after - or because of - an 11-year Blair leadership, many Labour MPs retain their social chips and class resentments. Until now, they had assumed that these were widely shared; that large sections of the electorate would automatically reject an old Etonian. On present evidence, this does not appear to be true, yet Labour has no Plan B.

It will certainly not come from Hilary Armstrong, the Labour Chief Whip. At Prime Minister's Questions, she was yelling abuse, as she often does. Mr Cameron skewered her. That was merely the small change of party warfare in the Commons; there were no grounds for rancour. But on Wednesday evening, when Mr Cameron saw Miss Armstrong, and took her a glass of champagne, she spurned the drink and launched into a tirade as to his temerity in singling her out for censure. She promised that next week she would shriek even louder. "Make my day, Hilary," responded Mr Cameron.

Miss Armstrong gives gracelessness a bad name. She only seems to think with her bile duct. It is time that someone took her to one side and told her that, whatever tactics Labour should adopt in dealing with Mr Cameron, noisy stupidity is not the answer.

Labour has to come up with an alternative, though Gordon Brown thinks that this is unnecessary. Even though he is vastly more sophisticated than Miss Armstrong, he seems to share her world view. He believes that Labour should just work away on class politics, while accusing Mr Cameron of regarding the public services as the wolf regards the sheepfold. When Mr Brown makes up his mind, it is impossible to persuade him to change it, so this is likely to be one of Labour's principal ploys at the next election. But it could only work if, against all expectations, the Cameron leadership declined into ineptitude.

There is one key fact that could determine the outcome of the next election: the current level of public expenditure. By the election, it will be approaching £600bn. Written out in full, that is a six plus 11 noughts; more than £10,000 a head for every man, woman and child in this country.

One might have thought that this formidable sum of money should provide schools that teach properly, policemen who catch criminals, and hospitals that do not infect their patients with life-threatening conditions. If the Tories cannot make that argument, they will deserve to lose.

At present, not one voter in 10 realises just how much public money the Government is spending. It should not be impossible to put that right. Nor should it be hard to persuade the voters about government waste. Even if only five per cent of public spending is wasted - surely a low estimate - that would amount to £30bn, which would be enough to pay for a fair few nurses, doctors, teachers and policemen - not to mention the odd tax cut.

For the next election, the Tories will not require a complex economic message, still less a mendacious one. They merely need to tell the truth and repeat the facts.

In the shorter term, Mr Cameron's early successes have given him a problem: how to maintain the momentum. He is determined not to rush into premature policy commitments. He agrees with Margaret Thatcher that in the early phase of opposition leadership direction is more important than detail. He does have one advantage. Like Tony Blair in 1994, he has aroused so much interest that, even if they contain little in the way of new content, his general statements will be reported.

That will even be true when he talks about party management. For the past few years, Tory activists have become obsessed with their own affairs. Left to themselves, they will talk of little else, oblivious to the yawns of the rest of the electorate. At Easter and Christmas, popes address both the "Urbi" - the city of Rome - and the "Orbi" - the world. It has long since been time for the Tory party to pay far less attention to its own city and far more to the world.

Yet Mr Cameron does believe, and rightly so, that his party needs to change. In particular, he is determined to ensure that there are more female parliamentary candidates. No doubt he will be successful in this. But there is a difficulty. Even if there are many more girls on the Tory benches after the election, it will be some years before the new crop ripens to ministerial fruition.

Back in 1992, Gillian Shephard was appointed to the Cabinet after only five years in the Commons. Gill had been a more than competent junior minister. She was also popular throughout the Commons; she is a delightful person. But she was given the employment brief just at the moment when unemployment was rising sharply. Suddenly, Labour MPs who used to smile at her started to shout at her. They meant it, for understandable reasons; a lot of their constituents were being thrown out of work. As a result, Gill came close to losing her nerve. She had not sufficient experience of adversity in the Commons to cope with a difficult portfolio in hard times.

That would be equally true of the new female MPs whom Mr Cameron hopes to see elected next time. So he will have to manage the problem of increased expectations. But at least the party should have lots of able young women to choose from. There will also be increased representation from ethnic minorities.

All this is likely to arouse much more public interest than seemed possible only a few weeks ago. But Mr Cameron knows that he must not exaggerate the voters' enthusiasm for the Tories' internal affairs. He intends to talk as much as possible about the issues that concern the public: health, education, crime, the environment, and all the other difficult questions that New Labour has failed to think through. Over the next few months, Mr Cameron and his colleagues will do a lot of thinking.

But he has made his central strategic assessment. Most voters now believe in high-class public services and an efficient economy. They will only give their support to a party that makes a plausible case on both. Mr Cameron intends to ensure that, next time, his party can win that battle.