Alan Rusbridger had faced calls to be removed from the role after disclosures that the newspaper’s former media editor, Roy Greenslade was supportive of the IRA
Mairia Cahill, who has alleged she was sexually abused by an IRA man at the age of 16, had called on the Taoiseach to consider Mr Rusbridger’s position on the body.
He said: “I was pleased to be invited by the Taoiseach to be part of the Future of the Media Commission.
“I was heartened by his backing for my continued involvement, along with the Culture and Media Minister, Catherine Martin.
“The unanimous support of my Commission colleagues was very important to me.
“The Commission is considering critical issues for Ireland and I don’t want my involvement to be a distraction from its work, so I have told its chair, Prof Brian MacCraith, that I will step down.”
A 2014 column written by Mr Greenslade called into question Ms Cahill’s claims that she was raped by an IRA member, and has prompted apologies from the newspaper.
Mr Greenslade claimed BBC reporters investigating the story “were too willing to accept Cahill’s story and did not point to countervailing evidence”.
Katherine Viner, who succeeded Mr Rusbridger as Guardian editor in 2015, has apologised to Ms Cahill.
A note has been added to the 2014 piece which reads: “The lack of disclosure was especially unfair to a vulnerable individual, and The Guardian has now apologised to Ms Cahill.”
Writing in The Guardian, Mr Rusbridger also apologised to Ms Cahill.
He wrote: “Given what he has now shared, I believe he should have avoided those topics – or, at the very least, have been consistent in letting readers know more about where he was coming from – especially as The Guardian’s own guidelines have long been explicit about declaring interests.
“In particular, Greenslade had criticised transparency in a 2014 piece about a BBC programme on Mairia Cahill’s claim of rape by an alleged IRA member. Given his own lack of transparency, that was, at best, hypocritical.
“The piece spectacularly fails on transparency grounds. Had Greenslade been open with me back in 2014, I would have been able to come to a different judgment about it overall.
“So I am sincerely sorry to Mairia Cahill, both for the article and for the upset it must have caused her. Both The Guardian and Greenslade have also apologised.”
Mr Greenslade recently said he had made contributions to the republican newspaper An Phoblacht during the Troubles under the pseudonym George King.
Writing in the British Journalism Review, he confessed to supporting the Republican movement, adding: “That is not to say, however, that I was not appalled by the carnage.”
The commission was set up by the Irish Government in September to examine the future of the media in Ireland.