A week is indeed a long time in politics. Nobody will be clearer about that this week than Peter Peacock, the Education Minister. Having had a relatively predictable ride recently, he now finds himself the victim of policy-making on the hoof. The Prime Minister gives an interview to the News of the World backing random drug tests for pupils in schools, the First Minister is forced by media demands to hint at (but not confirm) “action this day” along similar lines and Mr Peacock is bounced into writing a letter to the headteachers’ associations.

Like all politicians, Jack McConnell may not be unhappy at being rumbled facing both ways. Wily as he is (Henry McLeish, his predecessor, may prefer a different description), he got his weekend headlines anticipating a “crackdown” on drugs in schools. By the time Monday arrived, his Education Minister was rather less robustly asked to ask headteachers for their views.

Undoubtedly, their opinions are to the point: “We have enough powers as it is, including the power to exclude and the power to lift the phone and call the police.” Schools, after all, have long-established drug education programmes and most should have procedures for dealing with incidents. It is also worth pointing out that guidelines were considerably toughened up four years ago when, for example, schools were advised to retain vomit for tests where pupils are involved in drug-related incidents.

But, like the legislation on antisocial behaviour, it is never wise to underestimate politicians’ penchant for populism. Research undertaken throughout the UK and reported last month found that the overwhelming majority of parents wanted teenagers to face random drug-testing at school - and the concern was greatest in Scotland (TESS, January 9).