SIPTU members in Dublin Bus, Bus Éireann and Iarnród Éireann are planning a 24-hour stoppage from midnight on St Patrick's Day.
SIPTU's national industrial secretary, Michael Halpenny, said the move was in protest at the lack of meaningful progress made between Transport Minister Séamus Brennan and the unions in current talks on the future of public transport.
Mr Halpenny said the talks now lacked credibility because of the Minister's statement to the Fianna Fáil Ard Fheis, in which he said he still believed that franchising was the way to open up the bus market to competition.
He said the Minister's weekend comments were seen as undermining a commitment to enter talks to consider alternatives to franchising of routes.
