Yesterday marked Bus Éireann's fifth day of strike, and the Irish Rail and Dublin Bus may join.
The Bus Éireann strike began on Friday, affecting about 100,000 passengers who use the bus daily.
Bus Éireann staff are on strike over plans by the organisation to introduce "cost-saving efficiency measures" and changes in working conditions. They changes have not been agreed by the staff.
SIPTU, the union organisating the strike, have said that they may ballot workers in other bus and rail companies, including Irish Rail and Dublin Bus, to support the strike.
Rail services were disrupted in a number of locations, as Irish Rail workers did not pass strikers at railways shared with bus workers.
SIPTU organiser Willie Noone said that Dublin Bus and Irish Rail workers “believe that they are next in the firing line if management in Bus Éireann is allowed to force through cuts to wages and changes to conditions of employment of their staff ”.
The Bus Éireann board said expressed worry that they are losing money over the strike. The company are already experiencing financial difficulties.