Former Tánaiste Michael McDowell has brought all his skills as a negative political campaigner to the search for Ireland's greatest person by suggesting that Bono and Mary Robinson shouldn't be considered because they're not dead.

According to McDowell, who will tomorrow night champion Michael Collins in the first part of RTÉ's Ireland's Greatest series, the inclusion of the U2 singer and the former president on the shortlist is artificial, due to the fact they are still alive.

"It is a bit of an oddity that they are included. There was a British show along the same lines and each of those who were debated on were dead. Unusually, there are two in this series who are still alive and it is strange to be nominating them for Ireland's greatest when the sum total of their life still has not been established," he said.

"There is an issue there. Bertie Ahern could easily have been nominated for the accolade five years ago, but obviously time goes on and things can change. There is a certain artificiality to it, and that could be viewed as a problem."

McDowell described Collins as "Ireland's greatest person, and he is everybody's hero. I hope I come out tops for him, of course, but I haven't seen anyone else's versions so it is hard to know what way it will turn out."

Historian Diarmaid Ferriter said the inclusion of Irish personalities who are still alive is unavoidable due to the nature of online polling, the method used to pick the final five.

"Online voting and polling often gives a very immediate picture and can lack any long-term perspective and this is perhaps the case with the shortlist for Ireland's Greatest. It is inevitable therefore that we are going to end up with people on that list who are still alive, so the list may be a bit skewed."

Ferriter said some notable names did not make the final five.

"It is quite surprising that people like Daniel O'Connell or some of the best- known literary giants haven't made the final cut. Robinson is an unsurprising choice because she has been a mould breaker in terms of her span in the presidency, and Bono appears to be there because of the impact U2 have made globally," he said.

Economist David McWilliams is currently finishing filming his own documentary on Mary Robinson, while Dave Fanning, Joe Duffy and Miriam O'Callaghan are all set to present their shows on Bono, James Connolly and John Hume respectively over the coming weeks.

After the five separate documentaries air, there will be a debate between the presenters on the Late Late Show followed by a public vote before the eventual winner is announced.