Fianna Fail TDs will face sanctions if they don't support Simon Coveney in a vote of no confidence next week.
The motion has been tabled by Sinn Fein following the controversial Katherine Zappone appointment.
It says the Foreign Affairs Minister's handling of the situation amounted to cronyism and fell below the standard of government expected by the public.
Taoiseach Michael Martin says the no confidence motion is a classic opposition manoeuvre.
While Mayo Fianna Fáil deputy Dara Calleary has indicated he will support the Minister in the vote next week.