Teachers are threatening to work to rule as part of national industrial action, saying "staggeringly unlawful behaviour" by schools was swamping them with extra work.
NASUWT members could refuse to do photocopying, chase up truants, put up school displays or collect money from pupils.
The union voted yesterday to ballot on industrial action in January next year after hearing that schools were requiring teachers to perform administrative tasks when they should have been marking pupils' work and preparing lessons. The administrative tasks were outlawed under a national agreement with the Government in 2003. Classroom assistants were hired to do the work.
The motion called on the Government to force schools to comply with the agreement.
The debate follows a union survey of more than 16,000 teachers which found that 64 per cent did not feel they had a reasonable work-life balance.
Only one in five said that their workload had reduced since the agreement was introduced.Reuse content