A member of the Public Accounts Committee has said John McGuinness would be unsuitable to chair any potential banking inquiry.
Speaking to RTÉ's Morning Ireland, Labour TD for Galway West Derek Nolan said he feared any banking inquiry would be "prejudiced before it begins" if Mr McGuinness acted as chair.
Last week, Mr McGuinness answered questions from the PAC over controversial comments he made and on the judgement he exercised when he was a minister of state.
Mr Nolan claimed Mr McGuinness showed a "lack of discipline and a lack of judgement" in making "allegations without factual foundation" when questioned over his expenses and travel arrangements at last week's PAC meeting.
He said that Mr McGuinness had "disqualified himself" from being chair of any banking inquiry.
"He speculated that he had made enemies with the civil service because of his book, that civil servants were out to get him possibly because of how he chairs the committee and he made a very serious allegation that a government department is leaking against him."
However, Mr Nolan said he did not think Mr McGuinness should resign as chair of the Public Accounts Committee.
Mr Nolan also denied he was trying to slow the process of a banking inquiry down.
Mr McGuinness had been criticised for bringing his wife on government trips when he was a minister of state for trade at the Department of the Environment.
He was also asked last week about his son Andrew, who was employed in his department as a personal secretary.