The long summer holidays are almost upon us. The residents of the streets around our school will be taking a deep breath as the indigestibles are turned loose.

We more or less keep them in the classroom for most of the daylight hours during term, but soon six weeks of 24-hour mayhem will threaten.

Who are the indigestibles? Well, almost all secondary schools have a handful, and inner-city schools such as mine have 20 or so in each year group. Every kid has his or her individual traits, but there are common features.

It usually comes down to dysfunctional family life and parental neglect, sometimes with physical and verbal abuse. They usually have low literacy and numeracy skills and emotional and behavioural difficulties, often defined as attention deficit disorder. Put bluntly, they are pupils who have become alienated from learning due to persistent failure to do well.

These pupils - mainly boys - cannot sit still in class and will not accept normal boundaries for teacher-pupil relationships. They are fine, provided you do not challenge them with instructions.

Their demoralised parents either ignore school requests for meetings, or go to the opposite extreme of marching up and becoming abusive in defence of their offspring. I have lost count of the times I have heard an angry parent blame the teachers for not being able to control their child. But what sort of professional training can really prepare a teacher for the kind of mulish lack of co-operation that this hard core of disaffected pupils presents?

The indigestibles are beyond the pale for all the professionals who are supposed to work with them, both in and out of the classroom. Every type of professional has a devious way of limiting their exposure to them.

I was in a meeting the other day when this blatant fact became utterly clear to me for the first time. It was one of those “socially inclusive” multi-agency sessions with educational and clinical psychologists, special project literacy teachers and learning mentors.

Each complained at having these children and their families constantly referred to them. One of the psychologists said that one of his pupils presented problems which were too complex to make real headway with.

“Can’t you give us the kids a rung or two up, with fewer problems but whom we can really help?” is to paraphrase him pretty accurately. I couldn’t help thinking that this is exactly what the teachers I line-manage would like to say as they struggle in the classroom.

Then it was the turn of the specialist literacy project teacher, highly trained and paid out of money from a leading commercial organisation. “Give us poor readers but not the ones with the behaviour problems,” he reported to the meeting, “as it spoils our interventions.” But these children almost always combine poor reading with bad behaviour. To believe otherwise is wishful thinking.

So what happens to them? When we have been through every possible option with these reluctant professionals, we finally resort to saying that we cannot cope with a pupil in school. The most difficult - though by no means all of them - are permanently excluded or, more often than not, moved on informally to an off-site specialist provision. The Government’s policy on social inclusion has reduced this kind of resource to a minimum, so only the most behaviourally challenging get a place.

But, not surprisingly. the specialist centres don’t want too many of the really difficult ones either. They restrict their numbers rigidly and are quite happy to turn a blind eye to their indigestible truants, as keeping them on roll is a defence against being asked to take on any more. It is not unknown for them to send pupils back to the school if they are mucking around too much.

So the conclusion has to be that it is the mainstream classroom teachers who have to take the brunt of dealing with significant numbers of these children. If they are lucky they get in-class support from the school special needs departments but there isn’t enough of this to go around.

Surprise, surprise: special needs teachers and assistants try to limit their time with the worst kids as well. Even senior managers - let’s be honest - have strategies for minimising our contact with this indigestible element of the pupil population. We can’t control them any more than anyone else. And so it goes on.

Nobody has a solution to the low skills, lack of self- control and the underlying aggressive apathy of this hard-core minority. So the bad news is that some of it ends up excluded or truanting from mainstream or off-site units and causing trouble on the streets, occasionally being brought back in to school to the horror of senior managers, teachers, mentors and most educational professionals alike, with the exception of the attendance officers.

Up in high places, ministers and civil servants experiment with educational initiatives that transform standards in schools. But it ends up as displacement activity as this group, small minority though it is, keeps on hitting the system like waves rolling on to the beach.

The way that they destroy the good atmosphere of a classroom and strain the nerves of all those that work with them in school simply does not change.

Dealing with them is so tiring that we have to evade to self-preserve.

Meanwhile, the behaviour of a small minority has a huge effect on the majority of pupils.

When school is out, the indigestibles will be on their way to a park bench near you. Far more worrying though is that when they leave school for good the multi-agency game of pass the human parcel is over. Then we all have to swallow them.

winning the war 29 The author is a senior manager in a London secondary school