Thousands of commuters face widespread disruption from Monday.
Unions at Bus Éireann are to begin an all-out strike after the company announced a series of cost saving measures - which it says is necessary to ensure its financial sustainability.
The measures will see the closure of three routes - Derry-Dublin, Dublin-Clonmel, and Athlone-Westport - along with the reduction of a further two services between Dublin-Limerick and Dublin-Galway.
The Minister for Transport Shane Ross is calling on both sides to engage in further talks to resolve the dispute.
But General Secretary of the NBRU Dermot O'Leary says Minister Ross needs to step up: