A school has defended its use of 'time out' flash cards that pupils hold up when they want to take a break during lessons.
Around 40 pupils at Benjamin Britten High in Lowestoft, Suffolk, have the cards which can be waved at a teacher when they feel overwhelmed by 'complex and often confidential issues'.
There is no limit on their use, allowing cardholders to leave whenever they feel like it.
Critics say the scheme gives pupils carte blanche to walk out of lessons whenever they like.
But headteacher Andrew Hine defended it, saying the scheme was 'tailored to a minority of students who may be dealing with a range of issues, such as managing their anger responses; bereavement and family illness; issues relating to mental health problems'.
He told the Mail: "The way students use the cards is reviewed regularly and this is a major step in keeping students in mainstream lessons.
"The strategy has been key in reducing classroom disruption and allowing the rest of the class to continue learning."
However, Chris McGovern from the Campaign for Real Education told the newspaper: "This allows children to get out of lessons as a reward for poor behaviour and will be seen as a badge of honour.
"It's a topsy-turvy approach where the children are in charge of discipline rather than the teacher, which would tend to undermine the disciplinary structure. It is an admission of failure by the school – a last, desperate measure."
The laminated cards, which are printed with the pupil's name, are understood to have been introduced around three years ago.
The co-educational school – which has about 950 children – expects pupils who excuse themselves to go to the 'student office' where they are supervised by an adult.
The school said the cards are given to students following a 'review of their needs, often on the recommendation of external specialists'.Use of the card 'varies from student to student' and frequent use will 'trigger a review of that student's needs'.
Benjamin Britten High was put into special measures last October following an Ofsted report. Inspectors criticised weak teaching, low expectations of pupils, low-level disruption in lessons, widespread bullying and poor attendance.
Last year only 37 per cent of GCSE students achieved five A* to C grades including English and maths, well below the national target.