The number of social workers employed by the North Eastern Health Board is below that required and not at a comparable level to other health boards, according to IMPACT regional organiser Mr Peter Nolan.
IMPACT officials met the board yesterday and said they would take industrial action if satisfactory progress was not made before their next meeting in September.
It is understood the dispute is over staffing levels in the areas of child protection and foster care, where social workers have statutory obligations.
Figures presented at the meeting indicated there were 40 social workers in the area but the comparable figure in the Western Health Board or Mid-Western Health Board was 60.
Union officials have asked the NEHB to produce staffing proposals and also to respond to the frustration felt by staff, who believed they were not capable of delivering the expected level of service.
In a statement, the NEHB said it was "committed to working with IMPACT to ensure a satisfactory outcome".
IMPACT will next week ask its national executive to sanction industrial action, which has been approved by ballot. It was anticipated the request would be granted.
The ballot was called in July following a meeting of social workers in the region. Dissatisfaction with staffing levels and progress on the issue was discussed and the ballot was subsequently carried unanimously.
Social workers said a lot of their work was "crisis driven" and an amount of time could be spent working on one particular case. The North Eastern Health Board provides services for counties Louth, Meath, Cavan and Monaghan.