The Executive Council of SIPTU is expected to make a recommendation to its members on the new Croke Park deal today.
The council met earlier this month to discuss the issue, but said it would hold on off on advising members until today.
Siptu represents around 6,500 public sector workers.
Union president Jack O'Connor has previously said that public servants would be better served by one centralised agreement with the Government on pay and conditions, but says he isn't sure the current deal is the right one.
SIPTU members will begin voting next Tuesday and the result of all union ballots will be known next month.