The Association of School and College Leaders is due to hold a formal ballot for national strike action in England for the first time in its history.
The ASCL said the school funding crisis, the erosion of teacher and leader pay and conditions and staff shortages were the main factors behind the decision.
Government attempts to resolve the dispute in March were described by the union as “completely inadequate” – adding that a pay offer was rejected by 87% of the eligible members who voted.
Geoff Barton, general secretary of the ASCL, said: “ASCL has never before formally balloted at a national level and this is clearly a very significant step.
“The fact that we have reached this point reflects the desperate situation regarding inadequate funding, long-term pay erosion, teacher shortages, and the intransigence of a government which we can only conclude does not value the education workforce or recognise the severe pressures facing the sector.
“This action is taken as a last resort and with a heavy heart, but we cannot accept the continued damage to education caused by government neglect and complacency.”
The ASCL said an executive committee of senior elected members met on Wednesday afternoon and voted unanimously in favour of the ballot.
In a statement, the organisation said the vote will be held at a date to be fixed in the summer term, with any resulting strike action expected to take place during the autumn term.
Mr Barton said: “We have made every effort to resolve this matter through negotiations prior to reaching this point.
“Unfortunately, the Government’s offer has failed to sufficiently address pay and conditions and, critically, did not provide enough funding for even the meagre proposal it put forward.
“Following the rejection of the offer by all education unions involved – ASCL, NAHT, NEU and NASUWT – the Government has made no effort to reopen negotiations and has said only that the issue of pay will now revert to the School Teachers’ Review Body.”
The Department for Education has been contacted for comment.
