Bertie Ahern's former sidekick Royston Brady has accused the ex-Fianna Fáil leader of de­meaning the office of taoi­seach and has written to him asking him to make corrections to future editions of his auto­biography.

The Sunday Tribune has learned that the former lord mayor of Dublin wrote to Ahern last week seeking clarification of comments in his recently published book about the hijacking of Brady's father's taxi by loyalists during the Troubles.

The story was mentioned by Brady during his failed campaign to become a Fianna Fáil MEP in 2004, but became his undoing after claims it had been fabricated.

Brady was later vindicated by the discovery of a front page Irish Times article published on Friday 17 May 1974 – the day of the Dublin bombings – which reported the hijacking of two taxis in the capital the day before. One of these belonged to Edward, Royston's late father.

In his book, however, Ahern writes of the incident involving Royston Brady's father: "Apparently, that was true..."

In an interview with the Sunday Tribune, Royston Brady, who believes that sentence conveys less than full belief in the hijacking, said "It's typical Bertie – deny, deny, deny. He knew my dad a long number of years and my dad had gone through that story with him on numerous occasions. I know this because my dad lost his nerve for a long time afterwards but in the 1980s, he wanted to go back driving again. He needed a PSV license. Bertie actually wrote letters to the then justice minister Gerard Collins and the garda commissioner on his behalf".

The Sunday Tribune has seen copies of replies Bertie Ahern received from the minister for justice and garda commissioner after Ahern made representations on behalf of Edward Brady, whom he refers to elsewhere in his book as a "supporter".

In a letter sent to Ahern last week, Royston Brady writes: "The truth of the matter is that my dad had told you about this incident on a number of occasions as early as the mid-'80s. I was actually present in Kennedy's Pub one night when he told you what happened.

"All I ask is that when your publisher is running the next batch, you have this clarification added to reflect the truth. We agree on very little, but on one issue, there can be no dispute: my dad was a man of the highest integrity and I think as a fitting tribute to his memory, it's the least you can do."

Brady says he also objects to Ahern's assertion that Brady "lost it" during his 2004 election campaign by refusing "to turn up for interviews with the media so he looked as if he was running away".

"I am insulted that he is trying to portray that I lost the plot completely. The one thing I did is keep the head down because I was told not to say anything. In hindsight, who is the one that lost it? I feel sorry for the guy because with all the problems over the tribunal, he has talked himself out of another job – the presidency. I think it is classic in his book that he says he didn't get involved in what he says was my blame game after the election because he "didn't want the office of taoiseach dragged into a slagging match. He did nothing at the end but demean the office of taoiseach."

Now managing Rogans­town Hotel & Country Club in Dublin, Brady (36) plans to return to politics, "I know they are talking about a directly elected lord mayor of Dublin. I'd definitely be interested."

A spokeswoman for Ahern said "Bertie Ahern received a letter from Royston Brady just this morning [Friday] asking him would he clarify one issue in the book when it is being reprinted. He will look into this when he has a chance."