Commuters are facing disruption at the start of the upcoming bank holiday weekend as bus drivers announced plans for a strike.
Both nationwide Bus Eireann services and Dublin Bus routes in the capital will be impacted by the as yet undisclosed action on May 1.
The strike is in protest at government plans to privatise one in 10 bus services currently operated by the State transport companies.
The National Bus and Rail Union (NBRU) said its members voted overwhelmingly in favour of action on International Workers Day.
Dermot O'Leary, general secretary of the union, said further details on the strike will be revealed one week ahead of the date.
However, it will include a two hour protest march to the Dail between 11am to 1pm, with similar demostrations planned in towns and cities around the country.
"Despite over seven months of discussion at the Labour Relations Commission, the Government, in the guise of the National Transport Authority, have not moved a jot in addressing the concerns of bus workers," said Mr O'Leary.
"The NBRU has been consistent in our opposition to the transfer of any current Dublin Bus and Bus Eireann staff to private companies."
Mr O'Leary said the union's concerns about bus services, as well as the future of Irish Rail, have been "heightened" during the recent labour relations talks.
"There is a certain irony in bus workers having to take to the streets to highlight their plight on International Workers Day, a day which is synonymous with the Labour movement throughout the world," he added.
"We are now calling on the Labour Party to use their position in Government to halt the tendering process, to allow for actual negotiations to take place, a continuation of the current tendering process will inevitably lead to a race to the bottom in workers terms and conditions."
Dessie Ellis, Sinn Fein's transport spokesman, claimed privatisation of a 10th of Bus Eireann and Dublin Bus routes would threaten the future of the companies.
"These companies provide a service that we cannot afford to lose and good jobs which we must protect," he said.
"Their contribution to our society and our economy is immeasurable.
"For every country to be successful, a good place to live and to work, it needs quality transport infrastructure, public transport links and international connectivity."
Mr Ellis said investment in public transport was needed while loss-making routes which are economically and socially important should get government support.
Transport Minister Pascal Donohoe said both Dublin Bus and Bus Eireann were paid over 90 million euro in taxpayer subventions last year along with a further 90 million euro for new buses and fleet upgrades.
"I recently put on record my commitment to securing an increase in the subvention provided to the companies to deliver additional services and increased frequencies for commuters," he said.
"It is my strong belief that such taxpayer support for improved bus services should be given in conjunction with a degree of competition and I am committed to the tendering of 10% of bus routes being implemented by the National Transport Authority."
He added: "It must be noted that both Dublin Bus and Bus Eireann are open to compete for the routes being put out to tender."