Taoiseach Enda Kenny has labelled as "damaging" John McGuinness's remarks that the State should pay for ministers' spouses to travel on some trade missions.
Mr Kenny said the comments from the chairman of the Dáil Public Accounts Committee and Fianna Fáil TD "smacks of the abuse and arrogance we inherited after 14 years of government".
Speaking in Rome, the Taoiseach said the comments are a matter for Fianna Fáil leader Micheál Martin to reflect on.
Mr Kenny said: "I know I'm in Rome. The old saying is that Caesar's wife must be above reproach.
"This is the Public Accounts Committee. It is a matter of credibility in respect of politics and accountability."
However, Mr McGuinness has accused the Government of trying to politicise his position.
He said the Taoiseach was not aware of the full facts and that he thought it was appalling that the Taoiseach would politicise this.
Mr McGuinness said: "It is wrong that the Government should now try to undermine the only committee in the house that is holding it to account."
The former junior minister earlier said the rules on spouses travelling abroad with ministers should be updated to take account of "the modern family context".
The Irish Independent reported today that Mr McGuinness wanted to bring his wife with him on trade missions when he was a junior minister in 2007.
The paper reported that he suggested to civil servants that the taxpayer should pay for spouses to travel in certain circumstances.
The article was based on documents released under the Freedom of Information Act.
However, speaking on RTÉ's Morning Ireland, Mr McGuinness said it was always his intention to pay for his wife.
He said there was a case to be made sometimes for ministers to bring their spouses on foreign trips and for the 1959 regulations governing the area to be revised.
He said: "In terms of trade missions, the protocol is that the wife does not travel.
"But there are circumstances that should be considered when ministers are away on State business for long periods of time and, where they believe that their wife should travel, they should pay.
"There may be other circumstances where the minister can then make a case, within a new set of guidelines, where he believes the State should pay because work practices have certainly changed.
"The family is now central to everything and it may be that a minister might want to make that case."
Mr McGuinness said the minister could make such a case on family or health grounds.
Mr Martin has criticised the media for not focusing on the "energy" that the Government is "putting into trying to undermine the chair of [the] independent PAC".
McGrath calls for McGuinness to resign from PAC
Independent TD Finian McGrath called on Mr McGuinness to resign as chairman of the committee.
Fine Gael TD Simon Harris, who is a member of the committee, said Mr McGuinness should consider whether its credibility is being undermined.
He said the "revelations" about Mr McGuinness are "hugely distracting" to the work of the committee.
Minister of State for European Affairs Lucinda Creighton described the revelations as "bizarre", especially as Mr McGuinness has "very much taken the high moral ground on these issues" as chair of the PAC.
People Before Profit Alliance TD Richard Boyd Barrett said Mr McGuinness's position as chairman is "pretty untenable".
Mr Boyd Barrett said it was absolutely pathetic that a leading figure in the Opposition is still defending his position that overpaid ministers should be allowed to bring partners on trips abroad.