DART drivers have served strike notice for November 20th in a long-running dispute over pay.
They have also notified Iarnrod Eireann that any attempt to deploy new drivers or extend a full service to Greystones and Malahide, could lead to industrial action before then.
Talks on a "New Deal for DART Drivers" similar to that agreed for mainline drivers last summer broke down last week when the sides failed to agree on a differential for DART drivers over their mainline counterparts. DART drivers get a 20.5 per cent allowance for one-operator-only (OPO) working.
The company has resisted extending the differential for fear of the knock-on effect it could have throughout Iarnrod Eireann. It also says an alternative proposal from SIPTU and the National Bus and Railworkers Union would be unworkable.
This provides for drivers on a 48-hour week to be rostered for a maximum of eight hours and 12 minutes a day, or 41 hours in total.
Iarnrod Eireann's director of human resources, Mr John Keenan, said last night that such a system would be too restrictive to operate efficiently.
He said refusal by the unions to allow the company to deploy six newly trained drivers was delaying a full service to Greystones and Malahide, and jeopardising a late-night service over Christmas. "We asked them if there would be a problem if we even used the six new drivers to fill gaps in the existing service when other drivers were out sick. They say if we put one of them in they will stop work.
"That situation cannot be sustained. We have invested in 10 new carriages and extensions to Malahide and Greysones. We have 16 more new carriages coming in the spring. Ultimately we are hastening the day of privatisation if we cannot provide a service to customers," he said. Existing DART drivers were paid £8,000 each to allow new drivers into the system.