Ed Balls won plaudits with his plan to make all regulatory decisions on exams independent of ministers. A new independent regulator will answer to Parliament, though the schools secretary, will appoint members and decide its remit.

Ministers have no say over the marking of exams or tests under the present system, but perceptions of impropriety are said to be fuelling the annual dumbing-down debate when students get their A-level and GCSE grades each summer.

Yet I doubt that making the exam regulator more independent will stifle the sneerers so long as we still have competitive exam boards with little incentive to make exams tougher; or a system of marking where an A or a B, a level 4 or 5 varies in value from year to year and from paper to paper. Nor will it alter the mindset of commentators who long for the days when few went into higher education rather than the 42 per cent of young adults who go to university now.

But there is a more fundamental problem here: independence reinforces the notion that politicians cannot be trusted. Yet politicians, because they are elected, are more likely to act as guardians of standards than independent agencies are, especially where those agencies become creatures of a prevailing professional orthodoxy.

Take A-level resits, highlighted recently by The TES. David Blunkett, as education secretary, resisted suggestions that there should be unlimited resits (his successors thought differently). He and his ministers also insisted on synoptic tests at the end of A-level courses, not just modular assessment. Similarly, John Major, when Prime Minister, rightly reined in coursework; Ruth Kelly, as education secretary, more recently asked the Qualifications and Curriculum Authority to cut it further.

Or take the curriculum, still subject to ministerial approval. Independent minds would scrap the requirement to learn chronological history, locational geography and pre-1900 literature. It took political will to bring back phonics and give numeracy more time in the curriculum.

Now I’m sure there are plenty of disgruntled teachers and academic educationists who believe that some or all of those decisions were wrong. That’s not the point.

Politicians are elected. If the Tories were to win the election on a pledge to make history compulsory until 16, as Blunkett did for citizenship, then teachers who disagree can vote against them. But the Tories are entitled to make that promise and, if elected, to ensure it is kept.

Schools and education policy should not be the preserve of the professional elite. If society, through the ballot box, wants standards maintained or improved, then its elected representatives should be held accountable for providing that reassurance. They can’t do it by handing all their power to unelected quangos, whose instincts may tend towards introducing measures that militate against what the public wants.

I know the new body will nominally answer to Parliament. But it is the job of ministers to consider in detail the effects of policies within their brief in a way that few MPs could be expected to do.

Mr Balls should look back at what happened to Estelle Morris if he thinks the media won’t blame him if things go wrong. Morris had no control over A-level marking, yet felt forced to resign after finding herself at the centre of a storm over erroneous allegations that A-level grades had been fixed: ministers played no part in grading decisions, yet got the blame.

Of course ministers should have no power over grading decisions. But ministers like Estelle Morris should be able to make strategic decisions in the public interest.

And teaching unions or teachers who don’t like such policies should be able to influence, criticise and quiz ministers in the same way that parents, pupils and employers can. However, without responsibility, politicians have no power.