The debate about whether examination standards are in decline has gone around in circles in recent years. Those on one side of the argument point to soaring pass rates at GCSE and A-level and the increasing share of top grades awarded and question whether it is possible that children are getting steadily brighter every year.
Those on the other side cite improvements in teaching and deny that an increasing pass rate must mean easier exams (pointing out that no one complains when an increasing number of people pass their driving tests each year). Assertions are traded, motivations are questioned. A great deal of heat is created, but little light.
So the introduction of some fresh expert testimony into this sterile debate is welcome. As we report today, Mick Waters, a former official at the Qualifications and Curriculum Authority, claims to have overheard representatives from exam boards lobbying head teachers to choose their qualification over that of a competitor by implying that their test will be "easier" for students to pass.
The implication is that exam boards and schools are engaged in a conspiracy to increase the pass rate of pupils by lowering testing standards. Mr Waters' conclusion is that the present examination system is "diseased, almost corrupt". He also identifies a series of powerful vested interests in the education system that will, he argues, doggedly resist any reform effort.
Of course, this testimony alone does not provide conclusive proof of corruption in the exam system, or even of declining standards. But it should provide serious cause for concern. And it surely necessitates an independent inquiry.
There is nothing wrong, in theory, with competition between rival exam boards such as AQA and Edexcel on service and efficiency. But there is everything wrong with these boards competing by lowering standards, if that is what is happening. This is something on which those on all sides of the debate about the direction of modern education should be able to agree. If qualifications are devalued, it is the children that take them that are betrayed. There is nothing egalitarian about undermining standards. Indeed, those from less well-off backgrounds are liable to suffer most as the children from wealthier schools move to exams which maintain their quality.
Whatever an inquiry uncovers, it is already clear that the exams system requires a fully independent and powerful regulator. Ofqual, the existing watchdog (formed when the QCA was split in 2008), cannot be said to fit that bill since its leadership is appointed by the Education Secretary.
Yet as well as reforming the exam system, we need to consider why schools might have been susceptible to the sort of apparently corrupt behaviour from exam boards described by Mr Waters. This seems likely to be another malign consequence of the tyranny of government school league tables.
What began life as an initiative to increase the transparency of the performance of individual schools has evolved into a monster. There is now immense pressure on schools to reach arbitrary targets for the proportion of students passing a certain number of exams in order to maintain their positions in tables of performance.
It has long been clear that league tables are distorting educational priorities in the classroom. Lessons are dominated by preparation for endless exams. Creativity and enjoyment is often squeezed out of the educational experience. Yet it would now appear that the rottenness spread by league tables goes even deeper. Our examination system needs to be examined. But we must also address the structural distortions in modern education if we want to get to the heart of what ails our schools and impoverishes our childrens' education.