Leading article: Mr Brown shows that he is ready for the top job

When Gordon Brown rose to deliver his 10th consecutive Budget speech, he equalled a record set almost two centuries before. Which may be one reason why he was so keen to stress in conclusion that this was a Budget for Britain's future. The running subtext, though, was that this was a Budget not just for Britain's future but for his own future as well.

This was a speech in which the politics tracked the economics theme by theme, if not line by line. Mr Brown opened by rehearsing his achievements in managing the British economy over his decade as Chancellor - achievements of which he is justly proud, but which also constituted a barely disguised application for the top job. He concluded with what amounted to a mission statement for his hoped-for move to Number 10. It can hardly have been coincidence that Mr Brown not only claimed the achievements of the past 10 years as his own but set future priorities that were his, rather than a product of the collective wisdom of the Government as a whole.

Sounding loud and clear through Mr Brown's speech was also his awareness that the leader sitting on the Conservative benches, the man preparing to speak in reply, was his future rival in the next general election. As well as co-opting some of Mr Cameron's opening gambits as Conservative leader - his pitch for the green vote, his support for a youth volunteer service - Mr Brown allowed himself little taunts probing the quality of Mr Cameron's New Conservatism.

The Tory leader's response did everyone a favour by highlighting at least some of the glaring omissions in the Chancellor's speech: the funding shortfall in the NHS, Britain's lamentable productivity rates, the declining savings ratio and the fall in business investment. Mr Cameron offered some well-rehearsed ad-libs, but the tone was too strident and the substance too personal. We have heard him describe the Chancellor as a "roadblock to reform" often enough for it to sound more clumsy than clever.

The Brown-Cameron contest is shaping up to be an enjoyably edgy political duel. But the Conservative leader's response to Mr Brown was both more negative and more superficial than was strictly warranted. As Britain's financial manager, Gordon Brown has done a more than competent job.

He is justified in his boast that he brought an end to "boom and bust". He is justified, too, in drawing attention to the way in which the British economy has withstood successive international economic shocks, and in comparing the country's economic performance during his tenure favourably with that of many other economies, including those of the Eurozone. If this is Mr Brown's legacy as Chancellor and the foundation for his premiership, then it is fair to say that he could have done a great deal worse.

Given this record, the stress in the 2006-7 Budget, as Mr Brown presented it yesterday, was admirably forward-looking, with education, sport and children the chief beneficiaries. More money for school heads to spend - if it is new money, rather than money that has been shifted from one column to another - gives financial impetus to the greater autonomy of schools provided for in the Education Bill, and that is positive. So, too, is the expansion of science teaching and the streamlining of funding for research.

Additional money for sport is another plus, with schools Olympics to be held every year before the London Games an attractive idea. The Government may have come late to embracing the prospect of hosting the Olympics in London, but it seems at last to have warmed to the idea. It should be said, though, that without the loss of school playing fields and municipal swimming pools that has continued under this government, there would have been less ground to make up in the provision of sports facilities.

An independent board to be responsible for publishing official statistics is another positive move. Here, too, though, it is worth noting that the status of government statistics would not have become an issue, were it not for the suspicion that this spin-loving government had not been spinning its figures, too. That the trust issue extends as far as official statistics bears eloquent testimony to the liabilities Mr Blair will leave to his successor.

And this Budget, if it is Mr Brown's last, illustrates the weaknesses as well as the strengths of the Chancellor's approach to managing the economy. Take the environment. As a paper, we welcome the greater focus on green issues, even if it came about largely because of the new challenge from Mr Cameron. But the way Mr Brown tackled pollution from cars smacked of the tinkering for which he is renowned. The rise in excise duty on the most polluting vehicles is far less than the cost of a tank of petrol for one of these behemoths. It will take a far higher tax on gas-guzzlers to influence people's habits. By lowering the duty by different amounts on different classes of cars, Mr Brown has introduced needless complexity. By postponing the tax increase on petrol and declining (once again) to tax aviation fuel, Mr Brown also called this government's green credentials into question.

The Chancellor's instinctive preference for complexity over simplicity was evident, too, in the different ways in which more money was allocated to families with children. A little more on child benefit here, increased tax credit there, £5 on childcare vouchers and a bonus for child trust funds: it will be hard for the beneficiaries to calculate, let alone those who wrestle with administering tax credits. Against this, the traditional stuff of Budgets - the "health tax" on cigarettes, one penny on a pint of beer and nothing at all on the Chancellor's tot of whisky - seems blissfully straightforward.

Mr Brown made a point yesterday of exempting champagne (and English sparkling wine) from additional duty in anticipation of sporting celebrations to come. If this was his valediction as Chancellor in anticipation of a house-warming at Number 10, it was a bravura conclusion in which much cash appeared to be dispensed, and sleazier money dealings were eclipsed - but for how long? - by better news.