Notice of 48-hour work stoppages was served on management this morning
Dublin Bus drivers are to strike for six days next month as part of long-running dispute over pay.
Full-day work stoppages will be held on September 8th, 9th, 15th, 16th, 23rd and 24th.
Trade unions SIPTU and NBRU said notice of industrial action was served on management this morning.
Workers at the state-owned company were balloted this month after rejecting an 8.25% pay rise recommended by the Labour Court.
The two unions representing staff had sought increases of up to 31% to bring them in line with Luas drivers.
SIPTU organiser Owen Reidy said Dublin Bus employees remain prepared to engage in productivity discussions with management.
The drivers are seeking a 15% wage increase over three years, as well as a payment in lieu of an agreed 6% pay hike that was deferred in 2009, he said.
"Our members are engaged in a dispute with management concerning what they believe to be a reasonable and fair pay claim.
"Workers at the company have not had a pay increase for eight years.
"During that period, they have suffered reductions in earnings and have co-operated with three comprehensive restructurings of the company."
Mr Reidy also criticised cuts to state funding, which he said further undermined the transport service.
"Dublin Bus returned to profit in 2014," he said.
"Over the last five years, there has been an increase in passenger numbers and revenue is up 30%.
"However, during this period, the state subvention to the company has been reduced by a total of 24%."
'Russian roulette with a public transport service'
Dermot O'Leary, the general secretary of the NBRU, blamed Dublin Bus for failing to resolve the dispute.
"It seems that the company and the mandarins at the [Department of Transport] are prepared to play Russian roulette with a public transport service that underpins the social and economic fabric of our capital city...
"Our members’ desire is not to engage in a dispute which will discommode the very people who rely on this most practical, most necessary public service.
"However, the minister and the government have a responsibility to ensure that Dublin Bus is allowed to come back to the negotiating table with an improved offer."
Dublin Bus said it was "extremely disappointed" with the rejection of the Labour Court recommendation and subsequent strike notice.
"Any form of industrial action can only have a negative impact on our company and will inconvenience our customers," it said.
"It has the potential to undo the financial stability achieved in recent years."
The company said it hopes to avert planned work stoppages and plans to meet with the joint trade union group to outline its position.
Business group DublinTown also criticised the decision, calling for further efforts to resolve the dispute.
CEO Richard Guiney said: "We know that approximately 40% of people who come into Dublin city centre on a daily basis use the bus.
"We also know from experience with previous Luas and bus strikes that half of those people coming into the city will not come in if their mode of transport of choice is not available to them.
“We estimate that the strike will cost the city approximately €2.5m per day."