Secondary-school teachers in Scotland have voted overwhelmingly in favour of industrial action over concerns about the "excessive" workload caused by the new exams regime.
Members of the EIS teaching union are now set to take action short of strike action and could refuse to cooperate with the Scottish Qualifications Authority (SQA).
A total of 95 per cent of those balloted voted in favour of the move.
Teachers have repeatedly spoken out against the impact that the introduction of new National (similar to GCSE) and Higher (similar to A level) exams has had on their workload.
They have complained that the large amount of internal teacher assessment related to the qualifications is excessive.
An official review group set up to look at the issue concluded last month that teacher workload created by the new system was "unsustainable".
The union said members would "work to contract" with regard to some exams-related activity.
EIS general secretary Larry Flanagan said: "This ballot result reflects the frustration of Scotland's secondary teachers over the excessive assessment demands being placed on them and their pupils, particularly around unit assessments at National 5 and Higher. The EIS now has a very clear mandate to implement an immediate work-to-contract in relation to SQA activity."
A spokeswoman for Nicola Sturgeon said the first minister was "very disappointed" with the ballot result.
Mr Flanagan said: "It is not our intention that this action should impact directly on pupils and teachers will continue to teach classes normally and to assess pupils' work.
"We will be issuing guidance to our members advising which SQA-related activities they should withdraw cooperation from and which activities teachers should continue to undertake as normal."