Ulster Unionist Assembly member Sir Reg Empey has described as "colourful and one-sided" claims that he was central to a "plot" that also involved Mr Jeffrey Donaldson to oust Mr David Trimble as leader of the UUP.
Sir Reg, however, has confirmed that the leadership of the UUP "was an issue" in the summer and autumn of last year. He said he was happy now to support and uphold the Ulster Unionist Council's decision to re-elect Mr Trimble as leader.
A new biography of the Lagan Valley MP, Mr Donaldson, which is being serialised in the Belfast News Letter this week, details what is described as a "secret plot" involving pro and anti-Belfast Agreement Ulster Unionists to remove Mr Trimble as UUP leader.
Not by Might, A Journey in Faith and Politics by Noel Davidson also contains details of a 17-page discussion document prepared by Sir Reg last year which describes the UUP and its leadership as "dysfunctional".
The paper said that there was no trust within the party and that its overall organisation was a "shambles". It added that the UUP could not negotiate an agreement because "neither republicans nor Her Majesty's Governmentbelieve they are negotiating with a group of unionists who can deliver".
The book claims that Sir Reg was being primed to take over the leadership of the party but that at an Ulster Unionist Council meeting in September last year, where Mr Trimble was again ratified as leader, he lost the nerve to challenge Mr Trimble.
It adds that former Trimble allies such as MLAs Mr Danny Kennedy and Mr Fred Cobain, and MEP Mr Jim Nicholson, with Sir Reg at that time, held a number of meetings with anti-agreement Ulster Unionists such as Mr Donaldson, Mr David Burnside and Ms Arlene Foster, and that the Rev Martin Smyth MP and former leader, Lord Molyneaux, were also involved.
Mr Donaldson went on BBC Radio Ulster yesterday to state that Sir Reg attempted to oust Mr Trimble as leader but that he failed to pursue his opportunity at the Ulster Unionist Council meeting in September last year.
"I think, unfortunately, there were people on the pro-agreement wing of the Ulster Unionist Party who were saying in private, 'David Trimble must go' but just weren't prepared to stand up and be counted when it really mattered," he said.
"And if they had done that the Ulster Unionist Party might have been in a very different position today," added Mr Donaldson, who is now a senior member of the DUP.
Mr Donaldson also indicated that while some supported Sir Reg for the leadership around that period he hadn't personally subscribed to that view.
Sir Reg told The Irish Times last night that there was no secret plot last year. While confirming the discussions between the Yes and No sides of Ulster Unionism he said the sole purpose of the talks was to try to unify the party around an agreed policy.
"Regrettably that was not possible. And as there was no agreement on the main issue of policy, the issue of the leadership did not arise," he added.
He said he did not lose his nerve at the Ulster Unionist Council meeting. He said that when the policy matters could not be resolved, there was no question of seeking to remove Mr Trimble as leader.
Sir Reg, when asked did he now support Mr Trimble as leader, said his relations with Mr Trimble were "fine" and he supported and upheld the Council's decision to re-elect him. He added that since the upheaval of last year there had been improvements to party structure and organisation, which was partly triggered as a result of his 17-page document.
He said that Mr Trimble around that time in September 2003 knew the contents of the paper. Sir Reg added that he circulated the paper to party colleagues yesterday.He accused Mr Donaldson of releasing the document to the book's author.
"How could any political colleagues have confidential dealings with him when what they might say might be retold directly to the press," he added.
Mr Donaldson responded: "There is an old rule that you should not say something in private that you are not prepared to say in public."
Mr Trimble said: "Mr Donaldson's motives in raking up the past in this manner are obvious and will not in any way improve his standing in the minds of most people."