So far there are cameras in 28 classrooms
A school has installed CCTV cameras in classrooms in a bid to avoid disputes between teachers and pupils and to tackle theft, the deputy head has said.
The surveillance system, with at least 68 cameras, is in place at Stockwell Park High School, in south London, which is currently being rebuilt.
Deputy head teacher Mike Rush envisages the number of cameras doubling when the rest of the building is complete.
Unions have described the measure as "Big Brother-ish" and inappropriate.
The teacher said there were already cameras in 28 classrooms as well as corridors and stairwells, and there are 40 more outside.
A school introduces CCTV cameras
Mr Rush said that the reaction from staff, children and parents had been entirely supportive.
"The children are very happy here because they know they are on a school site where they are safe.
"They are in a position where they are not going to be robbed and harassed and so on. The parents are very happy with it.
"We've had no complaints from the teachers about it being a Big Brother system watching them all the time."
He said that the cameras could be used to resolve disputes about bullying, or if claims were made against teachers.
Access to the footage is tightly controlled and those who wish to use it must apply to the principal in writing, Mr Rush added.
The Association of Teachers and Lecturers said it had been told about four schools in Salford, in Greater Manchester, which installed similar systems in March.
General secretary Dr Mary Bousted said: "This all sounds very 'Big Brother-ish'.
"We have major reservations about using CCTV to monitor staff.
"It would be hard to see how teachers would act naturally if they knew they might be being watched all the time on camera.
Chris Keates, general secretary of teachers' union the NASUWT, said the cameras were inappropriate and a waste of money.
She said: "We do not support the use of cameras in this way and see no professional security or educational benefits to such systems."
And general secretary of the National Union of Teachers (NUT) Christine Blower said: "Of great concern is the potential for covert surveillance of pupils and staff."