Thousands of classroom assistants are to resume strike action in the North today to protest the regrading of posts.
Strike action began in October with a 10-day closure affecting over half of the North's special-needs schools.
The strike by 3,000 members of public service union Nipsa closed 27 of the North's 45 special schools and disrupted classes in many more mainstream schools. The latest action will see union members take two days of action each week until Christmas.
The North's Department of Education has denied that any classroom assistant will lose out in the job-evaluation scheme that is being negotiated.
Education Minister Caitríona Ruane has called for an end to the action, which she says risks the education of vulnerable children.
The strike is the culmination of a 12-year-old dispute over pay and conditions. Industrial action began when a job evaluation scheme carried out by employers resulted in what unions said was a pay cut.
Employers have offered an extra £15 million as a one-off payment to compensate for any losses. However, Nipsa said one-off payments of some £2,500 went little way to cover the loss of up to £2,000 a year for some.
Under the offer made last month, it was proposed there would be a regrading of all 7,000 classroom assistant jobs in the North, with up to half of posts upgraded at an annual cost of £3.5 million per annum.
It was also suggested there would be three new job titles: classroom assistant (general), classroom assistant (special needs) and classroom assistant (additional special needs), with new rates of pay depending on grade and service.