Granting teachers the power to search pupils for drugs and alcohol would destroy trust, teachers in Oxfordshire fear.

The measures could be brought in as part of a crackdown on unruly behaviour following a Government report recommending extending existing powers to search pupils for weapons.

The report by Sir Alan Steer, the Government's top adviser on behaviour in schools, said powers could also cover cigarettes and stolen property.

Ian Jones, a teacher at Peers School in Littlemore said: "Our schools are a safe haven for most children, an oasis of calm and order."

Mr Jones, who is also the negotiating officer for the Oxfordshire branch of the teaching union NASUWT, added: "On the few occasions when it might be worthwhile implementing measures such as searches I think it only right that these are carried out by a security firm.

"It is not a teacher's job and asking them to do this would ruin the relationship and trust between teacher and pupil.

"That trust is precious and makes schools the safe places they are."

At St Gregory the Great School, in Cowley, teacher Nick Rose welcomed the report, saying searching pupils for drugs and alcohol was a "great idea".

Mr Rose said: "Most schools already have a common agreement with pupils to search for stolen items, drugs and knives.

"We already have the powers to search for these things if there is a reasonable suspicion a child is carrying them. I think if there's trust between staff and students and relationships are good we usually find pupils are OK with it.

"We don't search students just for the hell of it, only if there's suspicion."

But Brenda Williams, secretary of the Oxfordshire branch of the National Union of Teachers and a teacher at Oxford's Larkrise Primary School, said: "This is such a difficult one.

"The moment you start talking about these kinds of measures it makes it seems as if every child is somehow involved in drugs, alcohol and knife crime when we know the reality is that's not the case.

"Teachers have always had certain powers relating to alcohol and drugs.

"We have to question whether we really want teachers to be in a position where they are having to search a child though. I'm not sure that's what teachers want.

"Teachers go to school to help the learning of every child, that's their job.

"The vast majority of Oxfordshire's schools are havens of peace so we need to keep all of this in perspective."