Cameras that monitor the performance of teachers have been condemned by school staff
One school in Southwark, South London has installed 100 cameras in the school building.
Stockwell Park High initially filmed the school's perimeter fences for security purposes but it now also films lessons in order to help staff improve their performance.
Dr Mary Bousted, general secretary of the Association for Teachers and Lecturers comma described the new initiative as "very Big Brotherish".
"Schools should not have to resort to technology to fight bullying and bad behaviour," she added.
Stockwell Park's headteacher Judette Tapper described the surveillance as a "useful tool in investigating and discouraging truancy".
The company who installed the system describes the cameras as a "valuable teaching aid".
Classwatch says that the system allows lessons to be reviewed for revision or for the benefit of children who need extra help.
Tapes of recorded lessons could also be used in teachers' portfolios or help with the assessment of trainees, says the company's website.