Commuters will face massive disruption after unions at Irish Rail confirmed their plans to strike between 6-9am on Bank Holiday Friday, October 23, as well as on November 6.
Intercity, DART and Commuter Services will all be disrupted throughout the morning rush.
Irish Rail says the action will be hugely damaging to the company, and will damage the interests of customers and employees.
For their part, SIPTU and the NBRU have said they want to be rewarded for previous improvements in productivity.
NBRU general secretary Dermot O’Leary said: "It is unfortunate that an arbitrary decision by management at the company to ignore a Labour Relations brokered agreement to discuss previous productivity contributions by drivers has led to a situation where the travelling public will be discommoded.
"Forcing staff into a scenario whereby they feel they have no other option but to take industrial action is no way to practice employee relations.
"The resolution to this issue lies with those within the company who have chosen conflict over adherence to agreements, responsibility to the taxpayer, their passengers and staff should be the dominant feature in addressing any industrial relations issue at the company."