Teachers in Northern Ireland have voted to take limited industrial action amid unrest over the disparity in pay and career opportunities between them and their counterparts in England and Wales.
Members of the Northern Ireland branch of the NASUWT voted 89 per cent in favour of taking action short of staging a walkout, from January 15.
Jerry Bartlett, the union's deputy general secretary, said the dispute over pay in the province had been going on for five years but the union had met with "constant obstruction and prevarication" from both direct rule ministers and the Northern Ireland Assembly's new education minister, Caitriona Ruane, of Sinn Fein.
It is understood that a teacher in Northern Ireland with advanced skills on the upper pay scale could be missing out on nearly Pounds 20,000 a year, compared with teachers in England and Wales, because of the lack of the assistant headteacher role.
Chris Keates, NASUWT's general secretary, said union members had "explored every option" to avoid industrial action but now had little choice.
"It reflects the deep frustration felt by teachers across Northern Ireland about the injustices they continue to suffer with regard to pay and conditions of service," she said.
As well as pay, teachers are also unhappy that job titles such as assistant headteacher that exist in schools across England and Wales are not offered in Northern Ireland. They claim this is a block to career opportunities.
NASUWT says it will not stage a walkout over the dispute as teachers do not want to affect pupils' learning, but the action will include refusal to cover for staff, carrying out clerical or administrative roles and attending only one meeting each week.
The Department of Education in Northern Ireland (DENI) said it had met representatives from the union late last month but admitted it was unable reach an agreement.
A department spokesman said: "In Northern Ireland, negotiations on the remuneration and conditions of service in grant-aided schools are conducted through the teacher negotiating committee.
"The NASUWT has withdrawn from this arrangement and there is no other mechanism for individual teacher unions to present separate claims on pay and conditions.
NASUWT has been encouraged to rejoin the established negotiating machinery. It is hoped industrial action can be avoided."
The decision to take action will be particularly unwelcome news for DENI, coming three months after a strike at Movilla High School in Newtownards, County Down.
In October, 25 NASUWT members walked out when they had their pay docked after refusing to teach a pupil they claimed assaulted a colleague. Classes did not resume for three weeks.
At the centre of the allegations was a 15-year-old boy who had just returned from a 10-day suspension. The child was ordered to appear at a juvenile court.