The union has instructed members not to comply with tasks that fail to meet the recommendations of a government working group on making the new curriculum less bureaucratic.
For instance, teachers may stop submitting daily or weekly plans or producing detailed folios that support pupil assessments.
NASUWT’s general secretary Chris Keates said: “Excessive workload is blighting teachers’ professional lives and affecting their health and wellbeing, yet the government and employers are failing to act.
“The reforms to the curriculum and qualifications systems have simply piled on the pressure. Recommendations made by a government working group set up to examine these issues are being ignored by employers and schools.
“With 87 per cent of teachers citing workload as their biggest concern and two-thirds considering leaving the profession all together, this situation cannot be allowed to continue. Teachers are tired, exhausted and disillusioned.”
Jane Peckham, national official for the NASUWT in Scotland, added: “This new instruction will help to address the specific burdens generated by the Curriculum for Excellence.
“The NASUWT has warned repeatedly that unless teachers’ terms and conditions are made statutory, schools and employers will simply fail to take the necessary action to address teachers’ concerns.”
Talented teachers are being driven out of the profession because of the burden of excessive workload, she added.
“Yet the government and employers fail to act. If it wasn’t for the NASUWT action already in place, this situation would be far worse.”
A spokesman for the SNP said: “We urge the NASUWT to pursue its concerns through discussions rather than industrial action, which would not be in the interests of anyone, least of all pupils and parents.
“We have made education, and specifically closing the attainment gap in order to give every child in Scotland the same chance in life, a key priority.