Over 1,500 clerical and administrative staff in the Eastern Regional Health Authority (ERHA) are to begin a series of one-day strikes on Monday.
According to IMPACT, this is because some 20 people have been appointed to positions with better pay and conditions than existing staff doing the same work.
The organisation claims the appointees are receiving packages worth up to £7,300 a year more than experienced staff. The action is not expected to disrupt services to the public, at least initially. The services most at risk are those provided through the three health board hospitals, Naas General, St Colmcille's in Loughlinstown, and the James Connolly Memorial in Blanchardstown. IMPACT official Mr Sean McHugh says the union will provide emergency hospital cover if required.
Initially, IMPACT is calling out groups of clerical and administrative staff at particular locations to picket the ERHA headquarters at Canal Road, Dublin. On Monday, for instance, staff based at Dr Stevens's hospital, Kingsbridge, will mount pickets at Canal Road.
Mr McHugh says there is "huge anger" over the appointments. About half of them are at clerical officer level but they range to senior management posts. Besides new recruits being put on the top of the 16-year clerical officer scale at £19,000, internal personnel promoted have also been placed at the top point of the senior administrative scale at £40,000.
He says under normal procedures they should be starting at £33,000 and clerical officers at £12,500.
If there is no resolution to the dispute, Mr McHugh warned, action may be extended to include groups such as community welfare officers.
A policy of non-co-operation with the ERHA is already in place. This is slowing work on next year's service plans for the region, the processing of medical cards and the preparing of answers to parliamentary questions.
A spokeswoman for the ERHA said it had admitted breaching procedures to IMPACT and had given undertakings this would not happen again. It was willing to discuss the issue with the relevant staff but IMPACT had refused the offer.
The ERHA attended intensive talks with the union this week, which proved unsuccessful. It has called on IMPACT to refer the matter jointly to the Labour Relations Commission. IMPACT has not taken up the invitation. Further contacts are expected between the sides over the weekend.