Sligo/Leitrim Fianna Fáil TD Marc MacSharry has resigned from the parliamentary party and will vote no confidence in Foreign Affairs Minister Simon Coveney.
The Dáil is debating the Sinn Fein no-confidence motion in Mr Coveney this evening, with a vote taking place later.
In his letter of resignation, Mr MacSharry said he was elected to serve a democratic republic, not one which applied different rules and sanctions depending on the identity or the position of people involved.
Yesterday, Deputy MacSharry formally requested that his parliamentary party meet no later than 4pm today to consider how TDs and Senators would approach the vote.
However, the meeting didn’t take place.
In his resignation letter, Deputy MacSharry said: “All Fianna Fáil party positioning and policy are being determined in a fashion consistent with an undemocratic totalitarian regime rather than that of a democratic socialist republican party of and for the people.
“I therefore have no option but to resign the Fianna Fáil parliamentary whip effective immediately and will be voting no confidence in Minister Coveney this evening.”