Bus Éireann has called unions to a meeting to discuss the company's financial position and to outline strategies to deal with challenges facing the organisation.
Among the difficulties facing the company are a fall in passenger numbers, rising fuel costs and a cut in its government subvention for operating unprofitable routes.
Passenger numbers have collapsed by 20% over the past three years, but have stabilised over the past year.
Fuel costs are set to rise by around 12% from €32.6m in 2011 to an estimated €36m this year.
In addition, the Government has cut Bus Éireann's public service obligation subvention by around 25% over the past three years.
This year alone the cut was €6m.
Concern has been voiced about the impact on the company of licences granted to private sector operators.
The company has cut 200 staff members under a Cost Recovery Plan instituted in 2009. The workforce now stands at around 2,500.
Bus Éireann has also reduced the frequency of some routes and has invested in new vehicles to reduce maintenance costs, which are more expensive on older buses.
General Secretary of the National Bus and Railworkers Union Michael Faherty said that staff had not received a pay increase under the 2009 Cost Recovery Plan.
Transport Minister Leo Varadkar said it was well-known that the financial position of CIE has been declining for a number of years - and that further cost reductions would be necessary.
He rejected suggestions by United Left Alliance TD Joan Collins that the company had deferred announcing cuts until after tomorrow's referendum.
He said no directive has been given to Irish Rail, Bus Éireann or Bus Átha Cliath to defer any tough decisions as a result of the referendum, adding that each company was continuing to engage in taking the necessary decisions to address the current very difficult trading environment.
