THE DEPUTY leader of the DUP, Peter Robinson, once told the British government that the proposed timetable for the powersharing deal with Sinn Féin was causing such "turmoil" in his party that it "had virtually thrown out Paisley as leader".
According to Tony Blair's former chief-of-staff, Jonathan Powell, this moment of high tension came during the St Andrews negotiations in October 2006.
In his book Great Hatred, Little Room, Powell notes that this was something he and Mr Blair "took with a pinch of salt".
However, reliable British sources have told The Irish Timesthat the episode confirmed "the singular act of courage" required of the Rev Ian Paisley when he finally agreed to enter into government with Sinn Féin - and Mr Robinson's crucial role in supporting him while ensuring maximum DUP unity ahead of the historic deal finally concluded in March 2007.
Mr Robinson - who is expected to succeed Dr Paisley as DUP leader in late May or early June - correctly divined the rebellious mood in the DUP on the first day of talks at St Andrews.
Mr Powell records that at one stage he received a note saying Dr Paisley wanted to see Mr Blair alone: "But it was clearly a misunderstanding because the whole DUP delegation came down and made a terrible fuss; they clearly thought we were trying to split Paisley off from his party and that became a running theme throughout the negotiation."
When Mr Blair did eventually see Dr Paisley alone, he found the DUP leader in "benign" mood: "He sensed that his community was ready to move and if republicans could do what was needed on policing, his instinct was to come to a deal quickly before things unravelled, and then hold an election in January."
However, senior DUP sources have separately confirmed Mr Powell's note that the prospect of an election in January 2007 triggered serious opposition to the DUP leader among those, led by MP Nigel Dodds, arguing for a longer timescale in which to "test" republican commitments.
Mr Powell writes: "He [Paisley] said the only thing that was necessary was for Sinn Féin to hold an ardfheis on policing before the executive was set up - the one thing Adams and McGuinness had now made clear we could not deliver. But when Paisley went back to his party there was serious opposition, particularly from Dodds, to such a short timescale. Robinson told us the DUP were in turmoil and had virtually thrown out Paisley as leader - something we took with a pinch of salt."
Tensions and divisions within the DUP also appear to have frustrated Sinn Féin's efforts over the longer term to establish whether Dr Paisley would eventually agree to share power.
Martin McGuinness appeared so confident of his party's secret "back channel" to the DUP at one point that he thought to stand-down Mr Powell during a key negotiation in 2004.
According to Mr Powell this happened in the autumn of that year following the Leeds Castle talks and before a hoped-for deal fell apart on the issue of a photographic record of IRA decommissioning. However, informed sources have told The Irish Timesthat republican efforts to satisfy themselves about Dr Paisley's disposition were complicated by the fact that Sinn Féin was talking to people in the DUP who started off taking a "softer" position than Dr Paisley but ended-up taking a more hardline attitude than their leader.