It comes after Minister for Transport Shane Ross said he would not interfere in the ongoing dispute
Unions say industrial action at Bus Éireann is now "an inevitability", after the company outlined a new series of cost-saving measures.
The unilateral measures, to be implemented in three weeks' time, would result in employee earnings falling by about 10%.
The plans include a blanket reduction in allowances, as well as cuts overtime rates, Sunday premiums, and sick pay benefits.
Dermot O'Leary from the National Bus and Railworkers Union said workers will not take the cuts lying down.
"Industrial action, based on that letter, is inevitable", he said. "The blame should be pointed at the company and the Department of Transport. Workers will react in a fashion bring industrial action to bear on the transport system of this country.
Meanwhile, Minister Shane Ross has reiterated that he will not interfere in the ongoing industrial dispute.
Speaking today, the Minister said he has made it absolutely clear that he would not be involved in any forum relating to the ongoing discourse.
"What I'm not going to do is interfere", he said. "Any forum which would interfere with the industrial dispute or involves me, the answer is - I will not get involved."
He also said his department has "no plans" to change the free travel pass, in response to a question on introducing a nominal fee to alleviate the company's financial situation.
Yesterday, the acting chief executive at Bus Éireann issued a plea to staff unions to engage in cost-cutting talks with the company "as a matter of urgency."
Appearing before the Oireachtas Transport Committee, Ray Hernan outlined the financial difficulties facing the company.
He said he is not "scaremongering" when he says the entire company could go out of business - with the loss of 2,600 jobs - if “drastic and decisive” action is not taken.
In a letter to staff last week, the company outlined a highly controversial survival plan involving redundancies, cuts in premium payments and out-sourcing.
Mr Hernan insisted that claims from trade unions that the cuts-backs could amount to losses of 30% for workers were not based on any facts.