No one likes the idea of cutting the length of the school week.

Some councils have proposed such a cut, only to perform a U-turn when faced with angry protests from parents, and even those who have supported it, such as the Association of Headteachers and Deputes in Scotland, have done so with a heavy heart. Now parents are raising the pressure by calling for a change in the law to make any cut in the school week illegal.

For anyone worried about ensuring their children receive the best education possible, such a change in the law might look tempting, but what would it really achieve? Apart from anything else, such a measure runs counter to the long-standing educational culture in Scotland, which has always been less proscriptive than other countries. Ministers in some countries will know exactly what is being taught and when in every classroom in the country, but the approach in Scotland has always been much more flexible.

Naturally, we expect local authorities to deliver the best education possible, but we also give them the freedom to deliver it in a way that suits their own circumstances with the money they have available. That is why there has been discomfort at any idea of banning certain subjects, such as creationism, or insisting on others. It is also partly why Cosla, the local council organisation, has protested so vehemently at the Scottish Government's recent attempts to lay down minimum teacher numbers across the country.

Teacher numbers and the length of the school week are similar in another way too, in that we should be cautious in using the length of a school week as a reliable measure of standards. The amount of time teachers spend teaching in Scotland is high compared with other European countries, and yet some of those countries do better than us in some international comparisons. The 25-hour week in Scotland is also not the result of any kind of analysis into what is best educationally; it is simply accepted practice.

Even so, it is understandable that parents are worried about any cut to the school week. First, there is the possible impact on childcare arrangements: when so many parents work full-time and when childcare is so expensive, finding additional out-of-school arrangements will not be easy or cheap. Secondly, there is the issue of what is lost if hours are cut. If two and a half hours is trimmed, what is lost: two and a half hours of fitness? Maths? English? It is hard to see how ten per cent of the school week can be cut without some impact on the breadth and depth of the pupils' education.

However, this does not mean a change in the law is required. How long children spend in school should be guided by educational rather than financial considerations, but a change in the law might simply lead to councils cutting in other areas that are not protected by law and where even more damage could be done. And local activism and democracy has already proved its worth in forcing councils to think again on the issue. Any council that is still considering a cut should watch and learn.