If the DUP and Sinn Féin cannot make an agreement and then carry it through, then Trimble's sacrifice of his party as the dominant force within unionism will have been for nothing. Does he accept that?

"No I don't accept that . . . if there is an agreement between Sinn Féin and the DUP in the course of the next year or two - yes, you can say this may be what secures the process and that the rest of the world won't care much about the balance of unionist forces. But in the long run, the Democratic Unionist Party cannot be the major vehicle for the unionist electorate . . . [ given the] increasing disenchantment about politics from the 'garden centre Prod' whose disenchantment is partly because politics can't achieve things but more because he dislikes the style, the character and particularly the sectarian manner of local politics.

"And the very strong sectarian element that exists within the DUP and is reflected in DUP politics is one that runs against the grain of unionism today. By unionism, I mean the people who identify themselves as a unionist, who are actual or potential unionist voters. So in the long run, they are not going to be able to be the vehicle for unionist opinion as a whole unless their U-turns over the [ Belfast] Agreement are then matched by even greater U-turns over their sectarianism."

I can understand that argument in the context of the internal unionist debate over the past 30 years. However, won't it lose its relevance to a considerable degree in a post-Paisley era? "The Free Presbyterian character of the DUP does not depend purely on Dr Paisley. It's in the DNA of that party."

So he does not accept that Peter Robinson or Nigel Dodds could assume the leadership and gradually reinvent the DUP? "No, they're not going to be able to adjust themselves to the increasingly secular character of politics. They will not be able to. I think where we are at in terms of the DUP having just got their nose in front of us in terms of the popular vote is I think temporary. 'Temporary' may on this occasion be a number of years; I'm not assuming that things are just going to automatically quickly flow back our way. And indeed, if the DUP provide the final coping stone to the efforts that we've made to secure the [ Belfast] Agreement, then there will be I imagine a short-term electoral benefit for them in so doing. I'm just making a point that, in view of the DNA of the party, they cannot in the long run provide the vehicle for moderate majority unionists."

Trimble entered into all of this to win back lost ground for unionism, with a determination above all to make sure unionism didn't again fall for "the blame game". . . How does Trimble see those dangers, particularly in light of what he has said about the DUP and its character? "I think the danger is that they may lack the capacity to deal with the situation that they're in."