The Labour Relations Commission has circulated proposals aimed at resolving the dispute at Iarnród Éireann which has disrupted services in the past week.
Rail passengers today again experienced some disruption as a result of a row over rostering, with this evening's 17.35 service from Heuston to Carlow cancelled.
Tomorrow's 06.30 Portlaoise to Heuston service is also cancelled.
Iarnród Éireann has advised passengers from Portlaoise, Portarlington and Monasterevin to use the 06.51hrs service, which will stop at Portarlington.
Customers from stations between Kildare and Heuston are advised to travel on the 06.59hrs Kildare to Heuston train.
Siptu and the National Bus and Rail Union deny action is taking place and say the cancellations are due to a shortage of train drivers on some newly expanded routes.
The company says the drivers are in breach of agreements that provide for services to be maintained until disputes procedures are exhausted, however.
Efforts to end the dispute over rostering before the Labour Relations Commission (LRC) failed yesterday. The LRC circulated proposals to resolve the row to all sides today.
The Commission is understood to have proposed a restoration of flexibilities to cover all services and a deadline for the talks process to conclude by April 30th.