Pressure is continuing to mount on communications minister Denis Naughten.
The Taoiseach was again forced to defend his Cabinet colleague over claims he tipped off a lobbyist about a decision on a proposed media takeover.
Answering questions in the Dáil, Leo Varadkar said: "Minister Naughten didn't do any favours for anyone. He didn't do any favours for Independent News and Media (INM), he didn't do any favours for Denis O'Brien.
"In fact his action was to delay the merger - delay the proposed merger between INM and Celtic Media by referring it to the Broadcasting Authority."
Last week Mr Naughten made an unscheduled statement to the Dail responding to claims that a PR firm passed details of a telephone call with the minister to a senior figure within INM, two months before his referral to the Broadcasting Authority of Ireland (BAI) was officially announced.
Mr Varadkar added: "In relation to the phone call with the lobbyist, Mr Naughten indicated that he would follow the law and be guided by official advice and that is of course what any official would do.
"I am not sure if that constitutes confidential information or not but in my mind it doesn't because that is what ministers will do - they will follow the law and be guided by official advice.
"He has said that he regrets he ever took the phone call. He has said that he regards it as a political mistake on his behalf and he has apologised for it today."
Fianna Fáil leader Micheál Martin said he believed a "serious error of judgment" had been made.
He said: "It is clear to me and most people that the minister made a serious error of judgment and his defence to date has been very poor in relation to that very serious error."
Later, he added: "When you give that commercially sensitive information to one party you are actually responsible for what happens with it down the line because you shouldn't give it in the first place because by giving it you know there are consequences in giving it.
"I find it difficult that you find it difficult to find the words to say that this was a wrong thing to do."