Getting 16-year-old Linda Playfoot to take her school to court for not letting her wear a ‘purity ring’ to classes was as clever a way of wrong-footing liberal folk as I’ve seen. Strict adherence to school uniforms is the sort of thing religious schools are famous for. A liberal is far more likely to want to allow a child to wear what he or she wishes than is an evangelical Christian. So a case was designed by Playfoot’s backers, a group called ‘Christian Concern for our Nation’, to make the rest of us look like the persecutors, trampling on the right of the young to proclaim their faith.

You could argue – I do argue – that schools shouldn’t ban jewellery. School uniforms, almost extinct in the 1970s, made an unwelcome comeback in the eras of Thatcher and Blair, just as faith schools have also increased their influence. So when my children went to school, my son’s teachers sometimes seemed to have little better to do than write me long letters about the length of his hair (it was too short, just as mine, forty years ago, had been too long.) My daughter once refused to wear a coat to school on a freezing December day, because the only one we could find was dark blue and she knew she would get into trouble because it wasn’t black.

I’d like to free teachers from the task of policing their pupils’ apparel, so they could get on with teaching. But that’s not what those manipulating Ms Playfoot want. They positively like policing apparel. They just want to police everyone else’s. They’d be the first to insist on the banning of other people’s jewellery. They want their ring to be the only one allowed. And if that leads anywhere, it leads to people being forced to wear the purity ring.

Francis Beckett is a journalist and author of 10 books. He blogs at http://francisbeckett.blogspot.com