Since 2007, schools have had the right to search pupils suspected of carrying weapons. Now those powers are being extended. A new law, proposed by the last government and due to come into force in September, will add alcohol, drugs and stolen goods to the list of items teachers can look for.
Asking pupils to walk through a knife scanner is one thing, but frisking them down in search of a few pills is a very different prospect - with obvious risks.
"The new bill gives schools considerable powers," says Peter Smith, a former senior police officer who now trains teachers in search techniques through his company Status Training. "It's vital that teachers know the rules and know how to carry out a search properly."
The guidance is clear. Personal searches can take place only if there are "reasonable grounds" for suspicion. They must be carried out by a teacher of the same sex as the person being searched, in the presence of another teacher, also of the same sex. And pupils can only be asked to remove items of clothing that will not reveal either skin or underwear - in most cases that means just blazers and shoes. Patting down of other clothing is allowed, but cannot be "indecent".
So if a pupil stashes something in their underwear there is not much a teacher can do about it. But that is an unlikely scenario, according to Mr Smith, who says the key to a successful search lies in understanding the "psychology of concealment".
"You need to identify the most likely hiding place, and that depends on what the item is and what it's going to be used for. If a boy is carrying a knife because he's scared of bullies, he'll keep it where he can get at it quickly - not taped to the inside of his thigh."
Not everyone thinks searching pupils is a good idea. Unions fear teachers could be putting themselves at risk of physical attack or false allegations - the Association of Teachers and Lecturers, for example, urges members only to take part in "consensual searches", such as asking a pupil to empty their pockets.
And it is not just the short-term consequences schools need to consider. Behaviour expert Paul Dix, of training consultancy Pivotal Education, warns that carrying out searches could fundamentally undermine the working relationship between teachers and pupils.
"This kind of legislation seems to come from another age," he says. "It's about power and control, and perpetuates a `them and us' mentality. Do teachers really want their pupils to see them as some kind of police figure?"
Mr Dix insists that schools should only carry out a search in truly exceptional circumstances, and even then only when a parent is present.
"Good teachers will find other ways," he says. "If they think a pupil has stolen something, they'll give them a chance to return it anonymously, tease it out of them. The best schools cultivate an atmosphere of mutual trust and respect. Searching pupils would destroy that completely."
Where you stand
- Searching without consent should be a last resort. Try other approaches first.
- Teachers are under no obligation to carry out searches.
- Searches should only be carried out by trained staff. www.statustraining.com
- Never carry out a search if there is any risk to your own safety. Instead, call the police.