Fianna Fáil and Green Party TDs will be forced to mount a renewed defence of Tánaiste Leo Varadkar after Sinn Féin tabled a motion of no-confidence in the Fine Gael leader over his decision to leak an unpublished GP contract to his friend.
The motion, which will be debated in the Dáil on Tuesday, will drag the leaking controversy into a second week.
Despite the misgivings of some in Fianna Fáil and the Greens, they will be expected to vote with the Coalition in opposing the motion under a commitment in the Programme for Government.
Mr Varadkar faced a Dáil grilling for two hours this week after it emerged he had leaked a confidential document to his GP friend Maitiú Ó Tuathail.
The then-Taoiseach shared an unpublished copy of a GP contract agreed by the Irish Medical Organisation (IMO) to Dr Ó Tuathail, who was president of a rival doctors union the National Association of General Practitioners (NAGP) at the time.
Sinn Féin tabled the motion "due to the seriousness of this situation and the fact that the Tánaiste has faced no sanction nor has he given a credible account for his actions".
Party leader Mary Lou McDonald claimed Taoiseach Micheál Martin "has decided to sit on his hands and take no action".
"The Opposition cannot sit idly by, so we have acted - this is the right thing to do and it is the necessary thing to do," she added.
Ms McDonald claimed the leak by Mr Varadkar "was not incompetence or a mistake" but was "a conscious decision by Leo Varadkar to give his friend insider information".
She argued that it is "more of the old Fine Gael behaviour where it is about who you know and insiders getting access to the corridors of power".
She added that it "undermines the public's confidence in politics".
The Tánaiste's spokesperson said Mr Varadkar "dealt with all the issues" relating to the controversy in his statement to the Dáil.
"This motion clearly shows that Sinn Féin isn't interested in what actually happened.
"They're only interested in political mudslinging, attacking the Irish Government at a time of national crisis and diverting attention from the unanswered questions about their receipt of public money in the North," the spokesperson added.
Some in Fianna Fáil, like Marc MacSharry and Jim O'Callaghan, have been highly critical of Mr Varadkar's actions.
Mr MacSharry offered little comment on the motion, saying: "Presumably the party will consider the matter next week."
Mr O'Callaghan did not respond to an attempt to contact him.
Senior Fianna Fáil TD Barry Cowen hit out at Sinn Féin for tabling the motion as "wasting valuable Dáil time".
He said he couldn't speak for his party or the Government but "as far as I'm concerned the Tánaiste's initial explanation and subsequent responses to the Dáil questions on the matter were sufficient".
Fine Gael TD Richard Bruton claimed the Sinn Féin motion is proof the rival party want to engage in "narrow tribal politics" and bring down the Government.