Minister Simon Coveney will face a no confidence motion later as the Dáil returns from its summer recess.
The Sinn Féin motion spurred by the controversy over Katherine Zappone's appointment as a UN Special Envoy is expected to dominate the first day back.
This is the the first Dáil session since TDs started their summer break in mid-July.
But between COVID-19 restrictions decisions and a number of self-inflicted scandals, the recess was far from quiet.
Foreign Affairs Minister Simon Coveney faces a no confidence motion this evening over his failed appointment of his former cabinet colleague Katherine Zappone as a UN Special Envoy.
Taoiseach Micheál Martin has warned Fianna Fáil TDs will face a six month suspension from the party if they fail to back Minister Coveney.
Mr Coveney himself has been in touch with coalition colleagues and expects to survive the vote.
Meanwhile, former minister Katherine Zappone is to be asked to appear before an Oireachtas Committee to answer questions about the controversy over the UN Special Envoy role.
Cabinet ministers have said they expect Government TDs to all back Simon Coveney in a motion of no confidence this evening, playing down the possibility of dissenting votes.
Many opposition parties and politicians have backed the Sinn Féin motion - including TDs in Labour, the Social Democrats and People Before Profit / Solidarity.
However, Tánaiste Leo Varadkar has said he believes Mr Coveney will survive.
He told Newstalk on Tuesday: "There isn't anyone in the Dáil, or any colleague, I would have more confidence in than Simon Coveney.
"I think we all make mistakes - we all mistakes in our lives and we all make mistakes in our jobs.
"Whether it would be proportionate for him to lose his job over it, I don't think so".
The Dáil is fully returning to Leinster House for the first time since the start of the pandemic from today.
The chamber will be around half capacity, with 78 TDs sitting in a chequerboard format with one seat between them.
However, all TDs will be allowed in the chamber for the confidence vote - with extra space in the lobbies and visitors gallery also being used to house deputies.
Additional reporting: Jack Quann