Fianna Fáil TD Marc MacSharry has said he has no confidence in Taoiseach Micheál Martin's handling of the Covid-19 pandemic.
Mr MacSharry criticised his party leader for the use of repeated lockdowns to suppress the spread of the virus, calling it the Government's "only strategy".
Following the party's record low ratings in recent opinion polls, there is mounting speculation of a move against Mr Martin, according to the Irish Examiner.
"No, I don't have confidence in his handling of the crisis," the Sligo TD told Newstalk.
Mr MacSharry also questioned the implications of making decisions based only from a health perspective, adding Ireland has been in lockdown for longer than anywhere else in the world.
He said Ireland has also failed to "think outside the box" in securing extra doses of the Covid-19 vaccines, before saying the EU has shown it has "no competence in health matters".
Despite his criticism, Mr MacSharry said he was not prepared to resign from the party.