Bus drivers at Bus Éireann and Dublin Bus will mount a one-day strike on Saturday 28 February in protest at 600 planned redundancies at the two State companies.
The decision was taken at a meeting of the national executive of the National Bus and Rail Union (NBRU) this afternoon.
A further two-day strike is planned for 9 and 10 March.
NBRU General Secretary Michael Faherty said the stoppage on 28 February would coincide with the sacking of 160 drivers at Dublin Bus.
Mr Faherty said: 'The drivers want to do something to support those being let go.
'Targeting new drivers on probation as an easy option to introduce cuts is an unfair and lazy way to make savings, and also impacts on the travelling public.
'The planned cuts and withdrawal of services will decimate rural Ireland, in particular the young, elderly, and unemployed who can't afford private transport.'
In a statement Dublin Bus says it has not yet received official notification of any industrial action by the drivers' unions.
The company says it has no choice but to implement the cost-cutting plan at the start of next month.
The Minister for Transport has said in the Dáil that he wants an efficient, effective transport service for the country, which meets the needs of customers.
Noel Dempsey said he had secured an investment of over €313m and there was not anymore money to give to the bus and rail companies.
He was responding to Labour Deputy Tommy Broughan who said the workers at Dublin Bus had voted to go on strike because of his handling of public transport policy. He asked the Minister why there was no voluntary redundancy option at Dublin Bus.
Taxi drivers staged another protest in Dublin today calling for a moratorium on new licences, as they say there is not enough work for the number of drivers now available in Dublin.