Workers have announced their intention to hold six days of work stoppages in September
The National Bus & Rail Union (NBRU) has urged caution over the possibility of a resolution to the Dublin Bus industrial dispute.
Staff have announced plans for six days of work stoppages next month as part of long-running dispute over pay.
The full-day strikes will be held on September 8th, 9th, 15th, 16th, 23rd and 24th.
SIPTU and NBRU said notice of the industrial action was served on management yesterday morning.
Workers at the state-owned company were balloted this month after rejecting an 8.25% pay increase recommended by the Labour Court.
Dublin Bus has said it will arrange a meeting with unions over the issue - a move which Transport Minister Shane Ross has welcomed.
However, the NBRU has said it 'advises caution' over the possibility of a resolution.
In a statement this evening, Dermot O'Leary of the NBRU said: “We share the sentiments expressed today by the Minister for Transport, however is important that the shareholder (Minister) would assist by using his good offices towards providing the necessary assistance to the Company to enable it to address the legitimate pay claim made on behalf of all staff.
"The NBRU will of course accept an invitation to meet with Dublin Bus [and] we will attend in resolution mode. We have already demonstrated along with trade union colleagues, that we are prepared to build our way towards realising the ambitions of our members on a step by step basis."
However he stressed that "the first building block in the process being the requirement for the Company to recognise and address the challenge thrown down by the rejection of the Labour Court Recommendation".