Communicorp, the Denis O'Brien-controlled radio group which owns the country's only two national commercial broadcasters, has instructed its staff that no Irish Times journalists should appear on its programmes.
The decision was communicated to all programme-makers by the company's chief executive, Adrian Serle, on Thursday morning.
Communicorp operates the nationwide stations Newstalk and Today FM, along with Dublin radio station 98FM, and music-driven stations Spin and Spin South West.
In his memo to staff, Mr Serle wrote that the decision had been taken because of "vile comments" made by Irish Times columnist Fintan O'Toole in an article on September 12th during the controversy over opinions expressed by Newstalk presenter George Hook about rape and responsibility.
In his column, Mr O'Toole had described Newstalk as "the most flagrantly sexist public organisation" in Ireland and said it was time for "anyone with a conscience to stay out of its airspace".
On September 16th, in response to a request for a right to reply to O'Toole from Newstalk managing editor Patricia Monahan, The Irish Times published an article in which she described the original article as "a disgrace" and "outrageously unfair" to the station's staff.
There was no further communication between Communicorp and The Irish Times on the issue until Tuesday of this week, when the newspaper received a letter from Mr Serle, demanding that "a full and unqualified retraction and apology" be published in the following day's newspaper and online. "If such an apology is not forthcoming then we will review our relationship with the Irish Times," he wrote.
In his memo to staff, Mr Serle informed them that The Irish Times had refused his demand for an apology. "We asked for the apology to be printed by the end of yesterday," he wrote. "This deadline has now passed."
Irish Times editor Paul O'Neill confirmed he had been informed of Communicorp's decision, but he said there were no grounds for an apology or for the retraction of the original column, which had also been sought. "Fintan was entitled to express his opinion and The Irish Times was entitled to publish it," he said.
Mr O’Neill pointed out that Ms Monahan had been given the opportunity promptly to respond to the original column. Her article “fully reflected the views of Newstalk staff and was published on the basis that it would conclude the matter”, he said. “Communicorp has chosen to raise it again almost three weeks later.”
"It is a matter for Communicorp to decide who participates in its programmes," Mr O'Neill added. "Equally, The Irish Times reserves the right to publish a wide range of opinion without fear or favour. We will continue to do so."
Labour leader Brendan Howlin expressed his concern at Communicorp’s decision and said his party would raise the matter with the Broadcasting Authority of Ireland (BAI). “Banning journalists because of criticism is why people worry about media concentration,” he tweeted.