Postal deliveries face possible disruption from midnight as staff who maintain key equipment in the four An Post mail centres commence strike action over cuts in pay.
The 36 staff in question are employed by contractor IO Systems, but are retained by An Post to maintain the automated postal processing machinery in the centres in Dublin, Cork, Portlaoise and Athlone.
The Communication Workers Union said the dispute arose on 31 August when IO Systems introduced shift and roster changes resulting in income reductions from significant overtime and premium payments.
The union instructed members not to cooperate with the changes and to stick to their existing work practices.
However, IO Systems confirmed that this month it only paid staff for hours they worked in compliance with the new rosters - resulting in pay cuts from 10 - 40%.
The strike notice issued by the CWU expires at midnight.
A spokesperson for IO Systems said the company has contingency plans to deal with the strike.
He noted that the dispute had already been heard by the Labour Court, the Labour Relations Commission and by two independent facilitators, without a resolution.
He noted that the Labour Court had backed the management's right to change the shifts, and said the dispute could be resolved if the workers abided by grievance procedures which required them to resolve the matter back to the Labour Court for a binding decision.
According to IO Systems, staff can make up to €100,000 when overtime and premium payments are included.
The Communications Workers Unions this evening strongly criticised these claims.
A spokesperson described the management claims as grossly disingenuous and misleading.
He said salary scales at IO Systems ranged from €27,200 to €56,000 - including shift praemia and after Labour Court reductions to shift praemia.
He said those figures do not include overtime - but that many of the workers in question do not receive overtime - including those in the Dublin mail centre.
He said the average salary was €45,100.
He did not rule out the possibility that someone may have earned €100,000 as claimed by IO Systems. However he said that would be a deliberate and gross misrepresentation of the picture on salary levels.
Sources said the timeframe for disruption would depend on whether the machinery maintained by IO Systems broke down without maintenance, and whether management attempted to maintain the equipment without the normal personnel.
An Post confirmed that industrial action could impact severely on operations, but it was impossible to assess the effect at this point.
A spokesperson stressed that the striking workers were employees of IO Systems, not An Post.
