Teachers at a secondary school in Sheffield are set to take strike action tomorrow as part of a national campaign to protect working conditions.
Talks between the National Union of Teachers (NUT) and management at Westfield Sports College broke down on Tuesday.
Sheffield NUT secretary Ben Morris said: "This action is being called under the union's national campaign to reduce workload pressures and implement agreed procedures in schools.
"We are trying to address a situation where 56 per cent of teachers nationally are saying they want to leave the profession because of ever-increasing workload and stress.
"The central issue at dispute is the management's insistence on conduct observations in the style of Ofsted. We want managers that support their staff and respect their professionalism."
Tomorrows's strike, due to begin at 6.45am, is the first of six. Further stoppages are planned on December 12, 13, 18, 19 and 20.
As Aslef's annual assembly of delegates begins in Edinburgh tomorrow the general secretary explains the challenges his members - and workers across the country - face