Ireland could face a snap election after the country's second largest party Fianna Fail submitted a motion of no confidence against the deputy prime minister.
Frances Fitzgerald, the deputy prime minister - or Tanaiste, will have to quit before the no confidence motion is debated or her minority government will collapse.
Rival parties Fianna Fail and Sinn Fein are both calling for Ms Fitzgerald to resign over a controversy involving a bid to discredit a Garda whistleblower.
But Ms Fitzgerald's fellow Fine Gael ministers have rallied to her defence.
Taoiseach Leo Varadkar, the prime minister, said Ms Fitzgerald was facing a "trumped up charge" put by political rivals.
The Fine Gael minority government had been held up by a confidence and supply arrangement with the main opposition party Fianna Fail.
In the Dail on Thursday, Ms Fitzgerald rejected allegations she was privy to the conspiracy aimed at discrediting the whistleblower Sergeant Maurice McCabe during an inquiry into his claims of bad policing.
Ms Fitzgerald said: "I am trying to provide answers. I am not trying to hide anything. I was not part of any conspiracy to undermine Sergeant McCabe. Quite the contrary."
This week a Government email emerged indicating the Tanaiste was told in 2015 about the tactics being used by Garda lawyers at an inquiry examining allegations of malpractice.
The note, written by the assistant secretary of the Department of Justice, alerted Ms Fitzgerald, then justice minister, that "a serious criminal complaint" which had always been denied by Sgt McCabe, was raised at the commission.
Last year it emerged the legal team appointed by the former Garda commissioner was instructed to question Sgt McCabe's motivation and credibility during the inquiry.