The union claims management have not engaged with them
Unions at Irish Rail are to ballot their staff on industrial action after it has been claimed that Iarnrod Éireann is not taking pay claims seriously.
SIPTU and National Bus and Railworkers Union (NBRU) members at Irish Rail are believed to be looking for pay increases of around 25%.
SIPTU has referred a claim for "a substantial pay increase" for its members in all grades of the company to the Workplace Relations Commission (WRC).
SIPTU says the refusal by Irish Rail management to engage "meaningfully" on the claim over recent weeks has resulted in its referral to the WRC.
Management were informed in a letter from SIPTU representatives yesterday.
The company is attempting to increase its DART frequency and had to postpone the plans in recent weeks.
Dermot O'Leary is the general-secretary of the NBRU. He told Newstalk Breakfast that his members are not blocking any progress at the company.