Talks between Irish Rail management and unions at the Labour Relations Commission have ended without agreement.
The two sides have been engaged in national talks over drivers' rosters and work efficiencies.
The dispute has caused disruption to rail services over the past three weeks.
It is understood that LRC facilator Tom Pomphrett will contact both sides in the morning.
This afternoon's services between three Dublin stations - Pearse, Connolly and Docklands - and Balbriggan and Clonsilla were cancelled because of the dispute.
Iarnród Éireann said it had cited the trade unions to the LRC for breach of agreements, which provide that full rail services should be maintained to customers while issues are being progressed through the company and state industrial relations machinery.
The company and trade unions have been engaged in national talks concerning drivers' rosters and work efficiencies, and despite the guarantee that trade unions have given under company-union agreements that services be maintained, a number of services have been affected.
On a daily basis since 11 February 2008, the 6.30am Portlaoise to Heuston and 5.35pm Heuston to Carlow services have been cancelled, and further cancellations occurred last weekend.
In addition, due to five unexpected illnesses amongst drivers at Connolly Station, the company said the following services were cancelled today (Monday 3 March):
14.46 Connolly - Clonsilla
15.30 Clonsilla - Docklands
16.20 Docklands - Clonsilla
17.12 Clonsilla - Docklands
17.38 Docklands - Clonsilla
18.14 Clonsilla - Connolly
Iarnród Éireann apologised to customers for the inconvenience caused.
No further disruption was expected this evening; however, tomorrow the 6.30am Portlaoise to Heuston and 5.35am Heuston to Carlow will again be cancelled. No further cancellations are expected at this time.
Minister for Transport Noel Dempsey has said those involved in the unofficial dispute should use the proper mechanisms to deal with their issues.
For more information on disrupted trains go to irishrail.ie.