National Association of Head Teachers to consult on strike action
A union representing many school principals in Northern Ireland is to consult them on industrial action.
The National Association of Head Teachers (NAHT) represents principals and vice-principals in around two-thirds of 1,100 schools.
The union has asked its members to support an option to take either strike action or action short of a strike.
NAHT NI president Geri Cameron said the move was in response to an "unprecedented" crisis in education.
NAHT members received news of the move in an email.
"We urge you to use your voice and your vote at this critical time for our profession and for the learners in our charge," it read.
A letter from Ms Cameron to school employers, including the Department of Education and Education Authority, was attached to the email.
She accused them of failing to adequately support school leaders during prolonged action by the teaching unions.
"The employers have continued to fail to resolve the current dispute and bring an end to industrial action," she said.
"[They] have failed to provide effective support to school leaders or recognition of the fact that our members have been placed in an impossible position of trying to maintain standards on behalf of pupils in an increasingly difficult climate.
"An inequitable and unfair burden is being placed on compliant school leaders. As a consequence, the health and well-being of school leaders is being put at risk."
While the NAHT has said it supports a pay rise for teachers, Ms Cameron's letter said the pressure on school leaders had become "intolerable".
NAHT members had previously decided not to progress to industrial action in a similar consultation in February 2017.
However, the union's leadership is now asking them to think again.
In a statement to BBC News NI, Ms Cameron said teachers and principals were at "breaking point".
"While we recognise the validity of action taken by other unions, the additional stress and workload on our membership is no longer tolerable," she said.
She added that "with no resolution in sight and with funding continuing to decline", the union needed to consult members "to decide our next step and consider industrial action of our own".
The current indicative ballot will close on 29 January and, depending on the result, could then lead to a formal strike ballot.