The aviation sector has suffered due to the Covid-19 pandemic
It's hitting out at their delay in adopting the EU traffic light system for international travel.
The airline's threatening to close its bases at Cork and Shannon airports this winter, and significantly cut flights from Dublin, Kerry and Knock.
It will make the remarks at the Oireachtas transport committee today.
Sinn Féin's transport spokesman, Darren O'Rourke, says he hopes Ryanair doesn't go ahead with its threat:
