Forty-three workers at An Post subsidiary SDS have now been suspended in an escalating row over the closure of the parcel delivery service next week.
It is understood that number could climb to 60 this evening.
Talks chaired by Labour Relations Commission facilitator, Tom Pomphrett, ended this evening without resolving the dispute.
The Communications Workers' Union insisted that all suspended staff should be returned to the payroll immediately to allow talks on arrangements for closing SDS to be completed.
It said management attempted to implement new arrangements before final agreement had been reached on terms for the closure.
SDS is due to shut on Monday with its operations being reintegrated into An Post. 270 staff are being made redundant.
Earlier today An Post confirmed the suspension of eight SDS workers.
A spokesperson for the company said workers had refused to load American parcel traffic to be transported to Portlaoise to be handled as part of the reintegration of SDS into An Post.
The company warned customers not to drop in packages to SDS, as it would not be in a position to handle them this evening.
