Transport Minister Noel Dempsey has criticised the train drivers involved in the dispute that has caused significant rail disruption over the past four days.
Speaking in Dublin today, Mr Dempsey said it was difficult for Iarnród Éireann to resolve the row when the drivers break existing agreements "willy-nilly".
He said he expected more from public sector workers and said the mechanisms were there to facilitate talks between the two sides.
The latest disruption is part of a long-running dispute relating to driver training.
It began late last week when a Cork based driver was suspended for refusing to drive a train involved in the training process.
Trade unions have accused Iarnród Éireann of deliberately triggering a confrontation over the matter.