For the Chancellor, at least, there have been some encouraging signs in recent weeks. After all, the IMF has boosted its forecasts for UK growth, and is now predicting that Britain will outperform both Germany and France this year. Unemployment is also coming down, for the first time since spring 2011, and an optimist might interpret March's mini-surge in retail sales as consumers getting into the swing of an improving outlook.

If only. In fact, there is still much to be concerned about. Retail experts explain last month's splurge as good-weather spending brought forward, and predict an accompanying slump on the high street this month. More worrying still, much of the improvement in the jobs market is down to the creation of part-time, rather than full-time, roles. And with inflation back on the rise and wages still falling in real terms, even those with jobs are more pessimistic than they were. One in four of us now expect our financial situation to worsen over the year ahead, a far higher proportion than six months ago.

People are right to be cautious. For all the turmoil of the past few years, the full implications of the financial crisis are only just beginning to be felt. Take yesterday's piece of half-way good news for George Osborne. There is no denying that annual borrowing in line with forecasts is a good thing. But Britain still faces another five years of belt-tightening; and the worst is yet to come, as the focus shifts from investment budgets to welfare and public services.

Neither is success guaranteed. The Chancellor may have met last year's borrowing target, but his longer-term goals are still far from secure, relying as they do on economic growth not far off 3 per cent in just two years' time. Given that GDP figures published this morning are expected to record growth flatlining at a measly 0.1 per cent in the first three months of this year, the challenge is prodigious.

In fairness, the Government is not wholly without ideas. Almost-hidden behind the details of the Budget, was a vision of Britain as a world-class service provider competing on a global stage that has much to recommend it. But with so many ordinary people facing immediate financial challenges, setting a strategic direction – while laudable – will not be enough. Indeed, as if to underline the point, the Prime Minister's export-boosting tour of Asia this month coincided with figures revealing that exports are actually falling, dragged down by anaemic demand from Europe and a wobble in growth markets such as China.

More than ever, therefore, the economy needs a credible, short-term growth plan. So far, the Chancellor has only tinkered. True, revisions to the planning system should help; as will ring-fenced infrastructure investment schemes. But such measures take time that Mr Osborne may not have. Until he can convince ordinary people there are effective levers he can pull, and that he is doing so, confidence will waver, consumer spending will suffer, and a vicious spiral of austerity and recession will threaten to undermine his efforts to repair the public finances.

It is not only the economic stakes that are high. There is also a very real price to be paid at the ballot box if, without a clear sense of where future growth will come from, public support for the Government's austerity programme wanes. In Europe the cracks are already beginning to show, not least in the tottering support for Nicolas Sarkozy in France. Mr Osborne need not necessarily borrow to stimulate the economy. But he must look more carefully at the growth implications of what is being spent. Most of all, he must do it quickly.