Strike action at Bus Éireann could escalate to include other semi-state transport firms, a union spokesman has warned today.
A member of the National Bus & Rail Union's national executive said that there is a "huge risk" that members at Irish Rail and Dublin Bus may follow them on to the picket lines.
Just 5% of Bus Éireann services are operating today as the rolling strike over a €5m cost-cutting plan runs into its second day.
There was also a further escalation in Cork today when striking drivers temporarily blocked a GoBus service to Dublin airport from leaving.
NBRU spokesman John Maloney said that staff at Iarnród Éireann and Dublin Bus want to become involved.
"Our members in the two companies are getting increasingly frustrated here," he said.
"Seeing their colleagues being treated like they're being treated, whereby we're available for talks, the company continuously say they're available for talks, obviously someone is stymying those talks, and it is with a level of frustration that our staff in the other two companies are echoing that they want to get involved."
Bus Éireann has advised customers to check www.buseireann.ie and national and local media for updates on bus services.
The following services only are currently operating:
Route 1 Dublin-Belfast No Bus Éireann services operating. Translink services are operating. Translink services are at 10:00, 11:00, 12:00, 13:00, 18:00, 19:00, 20:00, 21:00 and 22:00 EX Dublin. Services Ex Dublin will operate from Custom House Quay.
Route 33 Dublin-Derry no Bus Éireann services operating. Translink services are operating. Translink services are at 10:00, 13:00, 17:30 and 22:00. Services from Dublin will operate from Custom House Quay.
All services expected to operate with services operating from Dublin city centre will pick up at Georges Quay in Dublin and Patricks Quay in Cork.
Bus Éireann anticipates that School Transport Services will operate as normal today, but parents and guardians are advised to check www.buseireann.ie in the event of any change.
Approximately 2,500 School Transport ticket holders out of the 114,000 School Transport ticket holders use public transport services to travel to and from school and they may be affected by any disruption to public transport services tomorrow as a result of potential industrial action.
"Bus Éireann would like to apologise for any inconvenience caused to customers due to this industrial action," a statement said.