The NUT is currently conducting a ballot of their members on whether they are prepared to take discontinuous strike action in support of a dispute.
The dispute is with employers of teaching staff but cannot be resolved unless the Secretary of State exercises her statutory powers to achieve certain objectives.
The details and objectives are listed here in letters from the NUT to the Secretary of State and the National Employers Organisation for School Teachers (NEOST).
The ballot closes on 22 June 2016. Further information will be available once the outcome is known.