Irish Rail says it is seeking an urgent referral of pay and productivity proposals to the Labour Court.
It comes after a cost cutting plan was rejected by unions.
Iarnrod Eireann says the savings targeted in the proposals are essential to secure the financial viability of the company.
The company says each week that passes without these savings being secured costs the company an additional €100,000.
National Bus and Rail Union (NRBU) General Secretary Dermot O'Leary doesn't think it will result in industrial action:
Four out of five unions have rejected proposed pay cuts of between two and three per cen, after consultation with the Labour Relations Commission.
Unions say they were promised no further cuts until June 2015.
The spokesperson for Irish Rail, Barry Kenny explains: