Minister Simon Harris has denied leaking details of the appointment of Katherine Zappone from Cabinet.
The Minister was responding to an allegation by Sinn Féin's Matt Carthy in the Dáil last night.
Deputy Carthy alleged, under Dáil privilege, that Minister Harris was behind the Cabinet leak on the Zappone controversy.
Minister Harris has categorically denied being behind the leak - saying Carthy's claim is a clear misuse of Dáil privilege.
Speaking in the Dáil today, Minister Harris said: "I was named in this House in my absence - my unavoidable absence.
"What was said, in my view, was a misuse of Dáil privilege, and I want the record of this House to show it's untrue."
In separate comments to reporters, Minister Harris said Deputy Carthy's remarks were put forward "without any evidence whatsoever".
He suggested the comments would have been "defamatory" if they were said outside the Oireachtas.
Earlier, Fine Gael's Peter Burke said Sinn Féin should go to the gardaí if they believe there’s been a leak at Cabinet.
He said there's no evidence behind the allegation, suggesting Sinn Féin is "throwing muck at the wall and hoping some of it will stick".
Meanwhile, Fianna Fáil is dealing with the resignation of TD Marc MacSharry from the parliamentary party.
In a letter to the Taoiseach, Deputy MacSharry said the party's positioning and policy is being determined in an undemocratic, totalitarian way.
His resignation came just a few hours before the confidence vote in Simon Coveney - a vote Minister Coveney comfortably survived.
He said he had been “left with no option” but to resign the party whip effective immediately and confirmed he would vote no confidence in Minister Coveney.
It's the first time in the history of the Sligo-Leitrim constituency that it isn't represented by a Fianna Fáil TD.
Deputy MacSharry told Ocean FM no party leader has acted like Michéal Martin.
He said: "It's very sad to say it's a one-man show - everybody else is expected to row in blindly.
"They get to voice their view... but their views have no consequence as to the actions of the leader. That wasn't the case for any other leader."
While it does reduce their Dáil numbers, the Government still has a majority, and the Taoiseach's biggest internal critic is now on the outside.
Ministers today say they've now much more important things to get on with.