Everyone knows that corporal punishment has been abolished in the UK. But some school staff believe that any form of physical restraint is unlawful. This is a myth.

The law allows “such force as is necessary” to prevent a pupil from committing an offence, or causing damage to a person or property, or doing something that might prejudice the maintenance of good order and discipline.

There is no legal definition of “reasonable force”. The Circular 1098, which gave guidance on justifiable restraint, does not describe when it might be used with impunity. It concludes that all the circumstances surrounding particular misconduct must be taken into account. It then gives examples of when reasonable force might be justified. These include: one pupil fighting another; a pupil attacking a teacher; a pupil running in a corridor; and acts of vandalism and rough play.

The notes accompanying the Education and Inspections Act 2006 give another example: leading a pupil by the arm to enforce an instruction to leave the class.

The Violent Crime Reduction Act 2006 gives heads the power to authorise staff, not just teachers, to use reasonable force to search pupils if they suspect one is carrying a knife or other offensive weapon on school premises, or where a pupil is under the authority of staff, for example on a trip. The suspicion must be reasonable. In law this means using common sense. One case, for example, turned on the “smirk” on the face of a young man coming out of a known drug dealer’s house. A head could also claim reasonable suspicion if there is a strong rumour that a pupil is carrying a weapon. It is not necessary for someone to have seen it.

Heads should ensure they are clear about who is authorised to search pupils, and that they get appropriate training. It is not advisable any longer to assume that everyone in charge of children knows the limits of their powers.

Chris Lowe, Chief editor of Quick Guide Publishing, a trade union adviser and a former headteacher.