As predictable as complaints about the British summer weather is the annual ritual conducted to mark the publication of the A-level results. Just as we cannot be sure whether we are having a "barbecue summer" or not, there seems to be a radical uncertainty about what to think about A-levels. It doesn't help that the Conservative Party has performed another of its detoxification ceremonies. David Willetts, the shadow universities minister, yesterday criticised the Government for blocking progress towards its "target" of 50 per cent of the A-level age-group going to university.

Target? The Conservatives do not approve of targets – even if they have been downgraded to deadline-free aspirations. They specially did not approve of this one, suggesting (a) that it would devalue degrees and (b) that it was nanny-state bossiness for Whitehall to decide how many young people should go into higher education. But the heat has gone out of that dispute, with everyone agreeing on a new warm, fuzzy consensus that it is a jolly good thing for lots of young people to go to university, but it is up to each individual student to decide if they want to.

It was only earlier this week that Mr Cameron was condemning in tones of high moral outrage the profligacy of the Labour Government in managing the public finances. If public spending has to be cut, and cut deeply, as indeed it has been, it is posturing to the point of dishonesty to suggest that the Government ought to be spending more in accommodating this year's unexpected peak demand for university places.

But none of the main parties has been notably honest in saying where the public spending axe might fall (or where taxes might rise), so perhaps Mr Willetts should not be judged too harshly. The more serious issue is that a public spending crisis coincides with a turning point in the history of public exams in this country. At the top end of the scale, which attracts a disproportionate amount of attention, this is the last year of the undifferentiated three As.

Yesterday, about 40,000 A-level students, one eighth of the total, obtained straight As. Next year, results will be broken down by module: that may bring its own problems, in that private schools may gain an even greater advantage, but this newspaper believes that the solution to almost any problem is to publish more information rather than less. More fundamentally, we are reaching the point as a country where we cannot afford to ignore any longer the mis-match between A-levels and the educational needs of the greater number of students and the vast majority of employers. Ed Balls, the Schools Secretary, has tried bravely to reverse the cowardly mistake made by Tony Blair in rejecting the Tomlinson proposals to replace A-levels with a set of diplomas covering a much broader range of vocational and academic subjects.

But that really was an all-or-nothing choice. There is no point in continuing with diplomas side by side with A-levels, no matter how hard Mr Balls tries to push water uphill by suggesting that diplomas enjoy parity of esteem. They do not. So long as A-levels continue, diplomas will be seen as a vocational, second-best option.

It ought to be that the recession, the squeeze on the public finances and the lessening of the obsession with straight-A students should prompt politicians to be bold at last and adopt Ian Tomlinson's plan. All they have to do is go through his report and substitute "A-level" for "diploma" throughout.