Martin McGuinness gives a slight, almost casual shrug of the shoulders when it is put to him that few believe his claim that he has not been a member of the IRA since 1974. During his campaign to become President of Ireland, his assertion is being challenged by politicians, former security chiefs and the Dublin media. All allege that he was a key IRA figure during decades of violence.
He says: "I think people see me as someone very much associated with political agreement and, probably more than anything else, being able to build a relationship with loyalist leaders Ian Paisley and Peter Robinson. That's what they see as enormous.
"I know this is a debate that has been raging, but the media are more interested than the ordinary man and woman in the street. When I went to the all-Ireland final – Kerry against Dublin – I couldn't get away for an hour and a half with people coming up and wishing me all the best. Not one of them said, 'Martin, when did you leave the IRA?' But every one of them knew I was in the IRA at one stage."
Yes, but does he think they believe, as he insists, that his IRA career ended well over 30 years ago? "Does who believe me?" he asks. The majority of people. Again, a shrug. "I don't think the majority of people – to be quite honest – care," he says. "I think they see me as someone who was at one stage of my life in the IRA, but they see me in the round, as someone who was able to make peace."
So does he mind the media criticism? "It's perfectly understandable. I'm not in the least surprised. In fact, I'm not in the least annoyed. I only really get annoyed when people tell blatant lies."
The perception that Mr McGuinness is persisting in a lie is troubling for a great many people in Ireland, many of whom see his arrival in their presidential contest as an unwelcome cross-border intrusion. But more than a few are prepared to accept his stance with a McGuinness-style shrug, regarding it as something he has to maintain out of political or legal necessity. In other words, they regard it as a necessary fiction, a little green lie.
This approach of putting the pragmatic before the dogmatic has been apparent for some years in Northern Ireland, where the Sinn Fein leader is credited with successfully sharing power with Mr Paisley. Mr McGuinness was mentioned in last year's report into the Bloody Sunday shootings in his home city of Derry in 1972, which concluded that Mr McGuinness probably had a machine gun on that day but did not allege he opened fire.
When Mr Paisley's son, a Westminster MP, was asked if this made him imagine Mr McGuinness with a machine gun, he replied drily: "I never imagined him without it." Nonetheless, loyalists have been amicably governing alongside Sinn Fein. In this election the republicans are attempting to insert themselves into the political mainstream in the south, building on recent advances to the alarm of the conventional parties there.
As part of this effort Mr McGuinness is deploying language not usually associated with the republican movement: he does not denounce all IRA killings, but he does distance himself from some of them. Last week, for example, he described the 1987 Poppy Day bombing in Enniskillen, when the IRA killed 11 Protestant civilians, as "atrocious". He said he was ashamed of the republicans who carried it out.
Because they had killed civilians? "Absolutely." But what if service personnel had been killed? "Well, there was a war situation existing at the time. I wouldn't have condemned it, no." So he wouldn't be using the word "shame" now? "You would be asking me to say that what the IRA did in Derry, attacking the British Army, was wrong. I'm not going to do that."
The conflict in the city was bitter, he says, with a lot of people killed on all sides. "I lost a lot of friends at the hands of the British Army," he says. "The person who actually introduced me to my wife, Colm Keenan, was murdered by the British Army. He was a member of the IRA but he was unarmed."
The word "murdered" – would he apply it to anything the IRA did? This is a question that – when asked of IRA and Sinn Fein people – generally draws a flat rejection that any IRA action could be branded as murder. But from Mr McGuinness it produces a less combative response, and one that some in Ireland may see as a departure. "The IRA were involved in quite a number of incidents which resulted in the accidental killing of innocent people and the term used by the relatives of those people who were killed was that they were murdered," he says. "I wouldn't disagree with that. I'm not going to disagree with their analysis of what happened to their loved ones."
Is that the same as saying the IRA carried out murders? "It's the same as saying that I accept that, in the circumstances where innocent people lost their lives, then it's quite legitimate for the term murder to be used."
Another example of an apparent new sense of empathy with his old foe, the Army, came to light a few nights ago at a rally at Free Derry Corner, near his home. Addressing a crowd of almost 2,000, he said his heart went out to all those who lost loved ones as a result of the conflict. Then, to the surprise of many, he added: "I am also conscious of many British soldiers, members of the Royal Ulster Constabulary, members of the Ulster Defence Regiment, and my heart goes out to all their relatives."
Five hundred regular troops and 300 locally recruited security forces were killed in the Troubles. Most of these died at the hands of the IRA. "My speech was off the top of my head; it wasn't pre-planned," Mr McGuinness says. "I thought it only fair to mention that many British soldiers did lose their lives and the pain of their families is no different from the pain of my friends' families."
Can he win the election? It's what might be called a long shot, for he is third favourite of seven candidates. Sinn Fein has put him forward because a yawning gap opened up in the political market with the implosion of Fianna Fail earlier this year.
While Mr McGuinness is the biggest celebrity among those standing, his selling points are not his republican credentials but rather his personality and the fact that in the south Sinn Fein is determinedly anti-establishment. Many Irish voters remain angry with a political system that they blame for ruining the country's economy. Mr McGuinness will find most of his votes among the unemployed, the poorly paid and the debt-ridden. His hope is presumably that in the next few weeks much of the heat will go out of the debate on his IRA role, leaving him well-positioned to harvest the votes of the alienated when they go to the polls on 27 October.
He condemns "the disgraceful, terrible greed and selfishness, the massive salaries, bonuses and pensions that have been paid" to those who ran Ireland. If elected, he would draw only an average wage, as he already does in his present post as Northern Ireland's deputy first minister.
"I came to Dublin from Derry today," he says. "And the person who drove me gets exactly the same wage, subsistence, that I do. That's the sort of life I want to continue to lead if I'm elected the next President of Ireland."
A life in brief
* Born in 1950, Martin McGuinness has been a republican activist since the Troubles erupted in Northern Ireland in 1969. He has admitted being second-in-command of the IRA in Derry in 1972, where he had a reputation as a legendary streetfighter. He served two prison sentences for IRA membership but maintains he left the organisation in 1974.
In 2007, after years of negotiation, he and the loyalist leader Ian Paisley became joint heads of a new power-sharing government in Belfast. The two long-time enemies formed a relationship so close that they became known as "the Chuckle Brothers".
Mr McGuinness has stepped aside from his post as Northern Ireland's deputy first minister to contest this month's presidential election in the Irish Republic. Although the post carries no actual power, a McGuinness victory would be regarded as a monumental development.