Workers at Dublin Bus will go to the Labour Court on Thursday afternoon in a move aimed at securing pay increases of more than 30 per cent.
Staff at the State-owned bus company are seeking parity with the pay of Luas drivers who recently secured a new wage structure.
Luas drivers recently secured increases of about 18 per cent over four years following a lengthy dispute.
Bus workers have argued that the recent award to Luas drivers has widened the pay gap between the two groups.
It is understood Dublin Bus previously proposed increases of about 8 per cent over four years but that this was rejected by trade unions.
Siptu organiser, John Murphy, said: "The pay claim by our members in Dublin Bus envisages the creation of an agreement with a three-year duration that includes annual pay increases.
"Such an agreement should be in-line with the deal negotiated by Siptu representatives for our members working on the Luas light rail network that, we believe, sets the standard for transport workers in Ireland. "
“The Luas/Siptu agreement saw workers receive pay increases worth approximately 4 per cent per year. There is no reason why workers in a profitable state company should not receive similar or greater increases.
“Siptu members in Dublin Bus have not received a pay increase since 2008. Since then the workers have agreed and implemented several re-structuring plans. These plans have succeeded in securing major cost savings for Dublin Bus and in placing the finances of the company on a stable footing.”
Siptu said there had been a steady increase recorded over recent years in passenger numbers and annual revenue for Dublin Bus. It said this resulted in the company returning to profitability in late 2014.
“Taking into account the productivity increases achieved and wage restraint shown over the last eight years, our members in Dublin Bus are calling for pay rises to be granted that are not dependent on the implementation of any further cost saving measures.”
Siptu also said its members in Bus Éireann and Iarnrod Éireann were currently in the process of making pay claims in line with the 18 per cent pay settlement at Luas which the union said was in line with “the transport industry norm “.
The National Bus and Rail Union (NBRU) is seeking increases of over 30 per cent.
Dermot O’Leary, the general secretary of the NBRU, which also represents workers in Dublin Bus said: “Dublin Bus workers have made major sacrifices through two cost cutting plans, part of which was wage reductions and the non-payment of the six per cent owed from 2008.
“Throughout this period other workers in the taxpayer- funded public transport service were receiving pay increases taking them beyond the pay and conditions of bus drivers.”
He said the NBRU had previously succeeded in achieving a 20 per cent pay increase for bus workers in 2000 and was determined to recover lost ground and seek parity with Tram drivers.