The Impact union is warning industrial action could be on the cards, if it does not get commitments on Aer Lingus jobs.
It comes ahead of today's Cabinet meeting, where the proposed sale of the State's stake in the airline to IAG will be discussed.
It is reported that the group's bid will include measures to address concerns on the future of Heathrow slots, Cork and Shannon airports and jobs.
Matt Staunton, Impact's General Secretary, is to meet the Transport Minister Paschal Donohoe before Cabinet to discuss the issue, and he is determined to look after his members.
Mr Staunton said: "We can't do anything about the Government per se, however we will continue to look for these commitments on the security of our jobs.
"We can't rule out anything on that front.
"We will continue to demand those commitments and we might end up looking for ballots for industrial action to secure our members' interests."