Responding to a report by the BBC into the use of isolation booths in schools, Liberal Democrat Education spokesperson Layla Moran said:
"Isolation booths are barbaric, counterproductive and symbolic of a broken education system.
"More and more schools are picking up the pieces of local government cuts with increasingly stretched resources.
"People do not go into education to isolate pupils and dole out punishments reminiscent of custodial sentences. Government must make more funds available for schools so that behavioural issues can be managed in a proper way."