The National Bus and Rail workers union has lodged pay claims with public transport operators.
They are seeking better pay for drivers in Dublin Bus and Bus Éireann.
This is to bring them on a par with Luas drivers.
The Labour Court is expected to shortly hear a pay claim by Dublin Bus workers.
NBRU General Secretary Dermot O’Leary said: “Having taken the pain of cuts throughout the austerity years it is now long since past time that Bus Drivers were given due recognition in terms of pay.
“Our members are becoming increasingly angry that their pay and conditions have fallen behind those of their Luas counterparts.
“What is particularly galling for Bus drivers is the fact that both modes of transport are funded by the public purse, however when it comes to having to take cuts to pay, to effectively plug the gap created by Government stripping out the necessary funding required to support Transport provision it seems those in the CIE Companies are the only group of workers in the publicly funded transport space who have had to cough up.”