The threat of disruption to DART services has been lifted after drivers decided tonight not to engage in any industrial action in their dispute over pay.
Instead, SIPTU members decided to engage in the training and testing of new eight-carriage DARTs, which was due to begin tonight.
They have also decided not to ballot for official industrial action on the issue.
The testing phase had already been postponed for one day to allow union leaders time to consult with members.
DART drivers earlier rejected a Labour Court recommendation that they drive longer trains for no extra pay.
The drivers claim they are entitled to a pay rise for driving the longer trains as it involves greater productivity and responsibility.
However, Iarnród Éireann has rejected the claim and says drivers were already paid for the work in a deal struck five years ago.
