The General Secretary of the Public Service Executive Union Tom Geraghty has said the Croke Park agreement is "working" and therefore "should be maintained".
Mr Geraghty says more than 16,000 public servants have left the sector since 2009, while more than €2.3bn has been saved in providing public services.
The Public Service Executive Union is holding its annual conference in Galway today where the agreement is likely to top the agenda.
Speaking at an event in Dublin last night, the Minister for Public Expenditure and Reform Brendan Howlin described many parts of the public service as "not fit for purpose".
Mr Howlin said: "We need a leaner, more efficient, better integrated and responsive public service."