Bus Éireann has warned that without "drastic and decisive" action, the entire company, and not just its loss-making division Expressway, will go out of business in a short period of time with the loss of all its 2,600 jobs.
Acting CEO Ray Hernan says the company's financial situation is "critical" - with losses for 2016 now forecast to go as high as €9m.
The statement is contained in a submission by Mr Hernan to the Oireachtas Joint Committee on Transport, Tourism and Sport, which he will address on Wednesday.
Mr Hernan states bluntly: "This is not scaremongering: this is the stark reality of what this organisation now faces."
Last week, unions pledged to resist a series of cost-cutting measures presented by Bus Éireann including reductions in overtime, premium payments and possible job losses, which they claimed would cut staff earnings by up to 30%.
However, Mr Hernan strongly denies that the management team is targeting staff to fix the financial problems.
He says all structures and costs, including existing management structures, are being reviewed.
He pledges to safeguard basic pay and seek to protect the maximum number of viable jobs.
However, he also makes clear that significant opportunities for improved efficiency and cost competitiveness do exist as part of a long term solution.
Mr Hernan stresses that Expressway's losses cannot be reviewed in isolation from the rest of Bus Éireann - and that the solution must be found from within Bus Éireann's existing resources.
He says urgent engagement with staff and unions is now required to agree measures, stating: "I have already presented a detailed offer which must be implemented."
Mr Hernan notes that payroll and non-payroll costs are increasing more rapidly than revenue growth.
He says that losses in the order of €8-9m for 2016 will mean the company's total reserves are now depleted to around €7m, less than one year's reserves at the current rate of losses.
He warns that savings must be achieved, not only to reduce Bus Éireann's existing cost levels, but also to compensate for projected increases in insurance claims, higher fuel costs and upward pressure on pay.
He says increasing passenger numbers by twomillion last year - an increase of 6% - delivered higher losses, rather than an improved financial performance.
However he insists free travel subventions did not cause the company's problems, and increased revenue for those services will not fix them either.
Mr Hernan's submission states that Bus Éireann must accept that there will be more competition, and provide a service that delivers value for money for customers, the State and the taxpayer.
He says improved staff rostering and better utilisation of the fleet will provide the foundation for delivering a more efficient business capable of competing for new tenders - and "aggressively" defending the company’s position on existing commercial routes.
The Acting CEO pledges that where changes are required for commercial reasons on some Expressway routes, they will only be implemented after full consultation with the National Transport Authority, which retains responsibility for connectivity.
He says his immediate priority is to lead the company out of the crisis, and that he is confident that the problems can be resolved and the future of the company secured with the cooperation of staff.
However, unions have already balloted for industrial action in the event that Bus Éireann introduces changes without agreement, and have rejected a Bus Éireann invitation to talks tomorrow.
SIPTU Transport Organiser Willie Noone said the company was demanding a precondition that they accept proposals including possible compulsory redundancy, total flexibility, and a peace clause for up to four years where the company could do anything, adding that no union could accept that.
He said the unions would be meeting members of the Oireachtas at Leinster House tomorrow to explain the dispute.
National Bus and Rail Union General Secretary Dermot O'Leary said there was little point in going to the Labour Court, as management had failed to engage there before Christmas.
He said this was not a normal industrial relations dispute, and called for a forum involving all stakeholders including the National Transport Authority and the Department of Transport.
He said that they would only consider third party intervention provided there were no preconditions.