Update 3pm: The Tánaiste says he has confidence in Denis Naughten as Communications Minister.
Defending the minister, Simon Coveney said: "Yes, I do have confidence in Denis Naughten as Minister.
"I've known him for 20 years and I know him as a straight minister, just as he is a straight politician.
"He regrets the fact that this conversation took place, but in my view, he didn't do anything that constitutes giving inappropriate information to anybody."
Update 11.30am: Fianna Fail's Deputy Leader has said that Taoiseach Leo Varadkar must account for the Communications Minister Denis Naughten's handling of the INM controversy.
Dara Calleary claimed that Mr Varadkar "ran away last night" and that he "got away with a glib response to a very serious issue to a minister trying to separate the personal from the private".
Speaking on Today with Sean O'Rourke, Mr Calleary said that the Taoiseach must take responsibility for Mr Naughten's 'poor performance' in relation to the issue.
"The Taoiseach now needs to account for the Minister's handling of this issue. The Taoiseach needs to take responsibility for the very poor performance of the Minister in relation to this issue," said Mr Calleary.
"The Taoiseach needs to take questions and answer those questions around the complete lapse here.
"And that's what we want to hear from now, the Taoiseach cannot ignore his to responsibilities on this issue to Dáil Éireann either."
Earlier: Denis Naughten on tip-off claims: I have nothing to hide
Minister Denis Naughten has denied passing insider information to a PR executive amid claims he tipped him off about plans to refer a proposed media takeover to a regulator.
Denis Naughten told the Dáil it would have been preferable if the conversation with the executive about Independent News and Media's planned buyout of Celtic Media had not taken place, but he insisted he had acted within the "letter of the law".
"I have nothing to hide in relation to this," he said.
Mr Naughten made an unscheduled statement to the Dáil to respond to claims that the PR firm subsequently passed details of the discussion to a senior figure within INM, two months before the referral to the Broadcasting Authority of Ireland (BAI) was officially announced.
The minister acknowledged that he told Heneghan PR's Eoghan O' Neachtain - a former Government press secretary - that his "personal view" was a referral to the BAI was likely, but he said he stressed to him that the "definitive" decision would be based on future advice of officials.
Opposition leaders in the Dáil raised concerns about the claims reported by the Irish Times, in particular that Heneghan PR was acting for INM and forwarded Mr Naughten's position to then INM chairman Leslie Buckley, who in turn, it is claimed, sent it to INM's largest shareholder Denis O'Brien.
INM later dropped plans to buy the seven regional newspaper titles owned by Celtic Media.
Mr Naughten said there were clear guidelines on media plurality and concentration of ownership that indicated a referral was "always likely", given Mr O'Brien's already significant interests in the Irish media landscape.
— RTÉ News (@rtenews) April 18, 2018
"In fact I would have failed in my responsibilities under the law if I did not do so and would have been criticised in the House for not doing so," he said.
The minister added: "There is nothing wrong or inappropriate for me as a minister saying to anyone or the public that if the plan for a media merger continues I would take advice on sending it to the Broadcasting Authority of Ireland.
"This is not inside information, but simply a reflection of the legislation itself.
"I had no inside information to give.
"It may have been preferable if the conversation had not taken place but I was by no means expressing a definitive view, nor could I do so at that time, nor did I state that the view expressed was a confidential one, as the article seems to assert."
Mr Naughten was pressed by Fianna Fáil TD Timmy Dooley to explain comments he made in the Dáil around a month later, in December 2016, when he stated it would not be appropriate to make his views on the planned takeover known.
The minister again insisted he had not passed on insider information to Mr O' Neachtain .
Wednesday's Irish Times report alleged that the episode forms part of the affidavit compiled by Ireland's corporate watchdog as part of its bid to have inspectors appointed to probe governance arrangements at INM.
The Office of the Director of Corporate Enforcement (ODCE) has applied to the High Court for permission to inspect the workings of INM - a legal move the media giant is opposing.
The latest claims were aired in the Dáil chamber on Wednesday as the INM controversy again dominated exchanges between the Government and opposition parties.
Earlier, during leaders' questions, Taoiseach Leo Varadkar said it would have been better if the minister had not spoken to the PR executive.
But he insisted Mr Naughten had not compromised sensitive material.
"None of us have seen this affidavit and this is of course a matter before the courts," he said.
He added: "It doesn't appear to me that this is sensitive information or confidential information.
"It may be the case that the PR executive or the lobbyist claimed that it was, but that is part of what lobbyists do - they often take information that is publicly available or easily available and present it as being confidential in some way."
Fianna Fail leader Micheál Martin expressed concern.
"This may or may not have been a breach of new market abuse regulations," he told the Dáil.
He added: "Any reading of the situation would seem to suggest that the inside track is alive and well."
The insider culture in Irish public life on full display as Minister Naughten prevaricates and waffles— Mary Lou McDonald (@MaryLouMcDonald) April 18, 2018
Sinn Féin President Mary Lou McDonald said: "For all the guff about 'new politics', is this where we are at now?
"That the gold-plated few get access to ministers and get given a heads-up on decisions the minister has taken in advance. What kind of a way is that to conduct politics?"
Labour leader Brendan Howlin said the claims were "extraordinary".
INM said it would not comment on the claims "for legal reasons". Heneghan PR also declined to comment.