As a young woman Maria McGuire was one of the most wanted terrorists in the world: pin-up of the Irish republican movement, gunrunner, the glamorous face of political violence.

Her decision to leave the Provisional IRA and write a memoir led to a death sentence from her former comrades. For years she lived under assumed names, disguised her appearance, and moved from house to house until the memories dimmed. Then on Monday her three decades on the run ended when she was unmasked as Maria Gatland, a leading Tory councillor in Croydon.

Yesterday she spoke for the first time about her secret life.

Mrs Gatland, 60, had a comfortable childhood in Dublin. After graduating, she lived in Spain and became “idealistic, romantic and foolish” about the Irish republican movement. She returned to Ireland in 1971 to offer her services to the Provisional IRA, which saw how an attractive, middle-class woman graduate would broaden its appeal. “I allowed myself to be used, but I did not see it in that way,” she said. “I was just so pleased to be doing something, pleased to be involved.”

As a lapsed Roman Catholic who supported contraception and campaigned for women’s equality she upset the republican old guard. And her affair with David O’Connell, the IRA’s married chief of staff, did little to endear her to her comrades. But the couple were involved in one of the IRA’s most dramatic adventures. In September 1971 they went to Amsterdam to buy weapons. However, the police intercepted more than 160 crates of Czech-made bazookas, rocket launchers and grenades at Amsterdam airport. They fled and returned to a heroes’ welcome in Ireland.

“I obviously like very high levels of stress – it’s something that I seek,” she said. “It was glamorous, it was exciting. It is so difficult to explain in Ireland in those times, the feeling that things were changing and there was a chance of a united Ireland.”

Her decision to leave the Provisional IRA came when Mr Connell was sidelined by Seán MacStiofáin. She fled to England. William Whitelaw, the Home Secretary, seeing the propaganda value of an IRA defector, ensured that she was not arrested.

“I just walked away one evening. All I could take was a small case. I left everything, my whole life, behind,” she said. “I joined the IRA because I felt that I needed to do something but it was only after I saw the realities of a violent campaign – on both sides – I just couldn’t go on with it.”

Instead of seeking a quiet, anonymous life she told the inside story of the battle for control of the IRA in a series of newspaper interviews. “Being young, foolish and arrogant I thought people might be interested in what I have to say,” she said. “But in no way did I think of the consequences or the rest of my life.”

After arriving in England she was moved from hotel room to hotel room, always fearful of the unexpected knock at the door. In 1973 she arrived in Croydon to write her memoir, To Take Arms: My Year with the Provisional IRA. Even then she had to move regularly, use false names and change her appearance. “It was an extraordinary period,” she recalled. “You didn’t know who was working for who, who was following who.”

The book was a sensation. Its revelations about the divide in the IRA leadership, the support of the US senator Edward Kennedy, the Amsterdam trip and her affair with Mr O’Connell were highly damaging to the republican movement. An IRA court martial sentenced her to death.“I had left behind a cause I had believed in – rightly or wrongly – and suddenly my life was very empty,” she said. “I was drinking too much and mentally I wasn’t very strong.”She said that she regretted the pain that she had caused to Mr O’Connell’s family but strenuously denied the rumours of other affairs spread by the IRA leadership after her defection.

“I did have a relationship with David O’Connell. I was very involved with him for a while, very infatuated with him, but these things fade.”

Her life did change after meeting a businessman, Mervyn Gatland. They were married in 1976 and she reinvented herself as a loyal suburban wife. The explosion of violence in Ireland during the 1970s also altered her view on the armed stuggle. “I now abhor all violence – that is both official and nonofficial. It spawns more violence.”

In the early 1980s her husband developed a chronic lung condition, which dominated their lives until he died in 2004. A Tory activist, he encouraged his wife to fulfil his ambition to stand for the local council.

“I wanted to do something in the community and put something back,” Mrs Gatland said. “I am not talking about anything as grandiose as redemption. I had my doubts because of my past but I felt it was so long ago that it would not be a problem.”

In 2002 she became the first woman councillor for her ward. Two years later the Tories took control of Croydon council and the next year she became Cabinet member for education. But the 30 years of carefully woven deceit were to end on Monday evening. During a heated debate one of her political opponents referred to her as “Councillor McGuire” and mentioned a book. No one else understood the significance, but Mrs Gatland knew that the secret was out.

After a sleepless Monday night she contacted the Tory council leader. She admitted that she had been a member of the IRA and offered her resignation. An hour later he called back and accepted. “I am disappointed in the way the local party acted but I do understand it was a great shock to them,” Mrs Gatland said. “Perhaps I should have said, ‘Here is the book, this is what I did, make up your own minds’. They should not have reacted so quickly but I can understand they were worried about their reputation.”

But why did she did not tell them about her past when she was selected?“Things were not as safe then and I still thought I was a risk. But also I did not feel it was relevant to the person I am now – it is almost 40 years ago.”

Yet she says she has been overwhelmed by the support she has received this week. “One of the things I have always admired about the English is their tolerance,” she said. “I have been amazed by their understanding that someone is allowed to make mistakes in their past. I feel I have paid for it in a number of ways.”

Now she fears, once again, that not everyone has forgiven. For the first time in 30 years she is back in contact with the police, who have advised her on safety precautions. “But it is a relief to me that I can, at last, be the person I am — my past and all.”

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