On an emergency call, a few weeks ago, I responded to a request to visit the old music room. There I found a science class with a cover teacher in disarray. Several pupils out of their seats were encouraged to sit down and I returned to the school office.

A few minutes later I was again asked to visit the same classroom, this time by the flustered special educational needs co-ordinator. She had called for emergency support from her office, at the back of the music room.

“I don’t know why this class is here. It’s impossible for me to get on with my work. Can you sort them out?”

I start, once again, to ask the pupils to return to their seats.

“And those over there, and those - and him - he needs...”

This is getting a trifle irritating as neither I nor the Senco is in charge. I ask her to step outside.

“Do you want to sort this class out or would you like me to?”

“Oh, sorry. You go ahead.”

I re-enter the room in my calmest possible fashion. I don’t feel calm when I am teaching these pupils myself because they are all boys and every class is a challenge, but it is much easier when you enter a room to support someone else.

I proceed, very gently. I know that a tirade will not work. Even if I could get them all sitting up to attention I know that as soon as I leave they will start misbehaving as a collective sign of contempt for the supply teacher.

So I circulate around the room, praising the pupils who are working, to encourage everyone to focus on the work set. Do they understand what they have been asked to do? Yes.

They have been asked to make notes from a textbook without any guidance about how to organise the notes. No wonder they find it difficult to focus for a whole hour. This is a large bottom science set with a lot of literacy problems.

But my approach is relatively effective. They all like the encouragement, and those who have been working like the praise. They are now all in their seats. The supply teacher smiles at me and seems to feel supported.

At break the Senco catches up with me, apologises for the outburst and thanks me for my support. The strategy of keeping calm and using commonsense has worked. And I did not need to take any child out of class.

The emergency rota is a must in challenging schools. Senior teams often complain that it is misused, but when a child refuses to move how can teachers keep their authority without back-up? Personal abuse of the teacher can be common in such schools.

Should the child remain to be taught by that teacher? The removal of a child from the presence of their peers is the one immediate sanction that teachers have. All others are delayed sanctions and children in these schools know how to evade them.

If teachers are to maintain the order required to teach they must have the support of senior colleagues. If you want to establish an emergency rota system start by getting the senior team to agree on the principle. Then take it to the staff meeting.

You may find that middle managers want to support the idea either by participating in the rota or by establishing departmental rotas that ensure pupils have another class to go to.

This avoids having a “sin bin” where the poorly- behaved pupils spend time together.

Staff can nominate a class where they feel confident they could receive one or two extra pupils. Once a rota is established, staff feel supported by each other.