Commuters are facing further disruption in the New Year after it emerged that Bus Eireann staff are to be balloted over potential industrial action.
As Luas drivers prepare to down tools next month in a row over pay, the prospect of strike action by bus drivers increased significantly last night.
Union bosses have warned that planned changes to the bus network could result in a downgrade in pay and conditions for members.
The dispute centres around the Express national coach service which the company says is failing to make a commercial return on its routes.
But last night, the National Bus and Railway Union (NBRU) said its members will not "stand idly by" and allow their pay and conditions to be jeopardised.
The union's general secretary, Dermot O'Leary, heightened tensions with company management by claiming that changes to Expressway are being held off on until after the general election for political reasons.
"Staff at Bus Eireann have been overloaded with information coming at them sideways over recent months through constant negative references to the future of the Expressway model," Mr O'Leary said.
"Rumour, innuendo and comments from managers in relation to impending changes to Expressway is not an acceptable method of consultation.
"Furthermore, our members are not prepared to become pawns in a political game of 'not doing anything' that would cause upset to a sitting Government prior to an election," he added. The escalating row at Bus Eireann comes as almost 200 Luas drivers also prepare to strike, as revealed by this newspaper last week.
Tram drivers are widely expected to reject Labour Court proposals aimed at resolving a long-running row with management over pay and conditions.
This week's vote, if rejected, will be followed by an immediate ballot for industrial action.