Jim O'Callaghan or Darragh O'Brien should be the next Fianna Fáil leader, according to one exiled TD.
Marc MacSharry quit the Fianna Fáil parliamentary party last year after voting against a condo nfidence motion in Minister Simon Coveney.
Mr MacSharry told Newstalk: “My personal view is, with a party in the position Fianna Fáil is in; with some 53 seats in the Greater Dublin Area, I think the leader must come from Dublin.
“That brings the choice to Jim O’Callaghan, to Darragh O’Brien and perhaps as a dark horse, but he might decide it is for later in his career, Jack Chambers.
“I would say the leader is likely to come from that.
“If you were to emanate further out from Dublin from that, then Barry Cowan in the Midlands – but certainly, it would have to come from the Greater Dublin Area in my view.”
When presenter Pat Kenny said the Taoiseach "doesn’t come across as dictatorial", Mr MacSharry replied: “No he hides it very well indeed.”
“Unfortunately, as somebody who has been on his front bench, as somebody who knows him for 32 years and as somebody who was absolutely committed to his elevation to Taoiseach and indeed voted for him for that role, sadly it is a one-man show.
“Fianna Fáil parliamentary policy is determined by focus groups under his control through FF headquarters and not, unfortunately, from the immense talent that is within the ranks of the FF frontbenchers.”
The Taoiseach will step down from his role at the end of the year and some backbench TDs have called for him to give up the party leadership at the same time.
Last week, the Government won a confidence vote in the Dáil by a margin of 19 votes despite losing its majority due to TDs resigning the whip.
Minister for Agriculture Charlie McConalogue has backed Mr Martin to lead Fianna Fáil into the next general election.
He said: "There's a well-known phrase in sport of making an opportunity out of nothing and really this is what's happening here, we're seeing a media opportunity out of nothing.
"The feedback right across the country is that people regard Micheál Martin as an exceptional Taoiseach and someone we have been very lucky to have over the last few years, someone who has great credibility with the public."