If David Trimble is feeling the pressure he shows no sign of it. Returning home to the family on Saturday night after another full day canvassing, his thoughts turn naturally to the civilising qualities of food and drink.

From time to time his eye falls on the CD player. One suspects a favourite opera will be in full belt as soon as the interview is over. The children come and go about their business, oblivious to the constantly-ringing telephone and the stream of paper feeding through on the fax. Daphne Trimble sees to that, the latest draft of today's much-hyped big speech outlining her husband's "vision thing".

So much to do, so little time. Today's speech to a specially-invited group of businessmen; an endless round of media interviews, press conferences and the final whistlestop tour in search of votes. Yet it is clear that Mr Trimble's thoughts are firmly focused on events well beyond Thursday.

I have a go at disturbing his calm contemplation of the longer term. The DUP is predicting 30 seats at least for the anti-agreement bloc. The dissidents in his own ranks might tilt the balance Dr Paisley's way. And he hasn't helped himself, surely, with his handling of the prisoner release (Sentences) Bill.

The UUP leader brushes aside all the "froth". He has now rationalised his vote against the Bill: unionists are against prisoner releases "as a matter of principle", his vote didn't endanger the agreement, and had he gone to Westminster last Thursday his party divisions would have been still "more dramatically displayed".

Mr Trimble insists those divisions are not impacting on the ground; that Assembly candidates who campaigned for a No vote last month are now "on board"; and that the anti-agreement forces will be "badly beaten" on Thursday.

Is he really predicting the effective demise of Dr Paisley and of Paisleyism come the weekend? Mr Trimble replies: "Not the effective demise of that but a further defeat for the rejectionist front. I think that's important because we need to see, and I think it is the case, that people are moving behind this agreement."

So, to that agreement. How does David Trimble - a successor to Carson and Brookeborough - feel at the prospect of sitting in government with Sinn Fein?

He laughs as he notes a crucial omission. "You left out Craig. Now that's an interesting slip because Craig did what you're mentioning effectively. Craig made a pact with Michael Collins when Collins was largely directing the IRA terrorist campaign against Craig's government. And Craig put in train a series of co-operative ventures which involved a joint committee on policing, which had his and Collins's representatives sitting together dealing with the matter. A very interesting parallel with our present times."

Obviously, Mr Trimble is more comfortable as successor to Craig than either Carson or Brookeborough (more laughter). So how does Craig's successor feel knowing he'll soon be sitting in government with Sinn Fein?

"Well, will they?" comes the reply. "There are a number of assumptions in that. Those assumptions depend on how Sinn Fein tackles the issue of establishing their credentials. The agreement is clear . . . and it does offer the opportunity of office to all parties with any significant support . . . that those offices can only be taken by people who are clearly established to the democratic process. The agreement is also clear that if they are not so established, they should be excluded or expelled."

Rather than focus on what he thinks should be done, Mr Trimble says: "The question should be put to Sinn Fein. What are they proposing to do, knowing they have an immense credibility gap, knowing they've done nothing at all to show that the war is over? What do they propose to do over the next few months to show that they qualify for office?"

I put it to him that, on the back of the mandate it will win on Thursday, Sinn Fein will claim its seats in the Executive as of right, as spelt out in the Belfast Agreement. Mr Trimble insists: "Ah no, no. That is failing to observe what is in the agreement. It contains the opportunity of office, yes. But only if there are those commitments to the democratic process . . . "

Does he really mean that the IRA has to have begun actual decommissioning before Sinn Fein is eligible?

"That is one of the things that's involved in showing that they are committed to the democratic process, and another is starting to dismantle the paramilitary structures."

But isn't this a needless diversion? Isn't the reality that by their willingness to enter a democratic government Mr Adams, Mr McGuinness and others are signalling that the war is over?

Mr Trimble appears unconvinced. "If that is the case - that they have abandoned terrorism in their own minds and are looking to a purely democratic future - they would themselves want to deal with these issues."

The UUP leader says "trust to rust" is so much rubbish. If the weaponry is not disposed of it can fall into the hands of other militant republicans "intent on trying to do what Mr Adams set out to do 30 years ago". He continues: "Mr Adams will not want that to happen. If they are genuine about this, then they will want to find ways . . . their own ways, perhaps . . . in which to deal with these matters".

Is he then saying that, as of now, he doesn't know if he will ever sit in government with Sinn Fein? Mr Trimble resists such "sweeping" statements. "Let's wait and see what happens and how the next few months evolve. That means waiting to see whether Sinn Fein are genuine and really intend this to happen."

Wouldn't it be more likely to happen if he would talk directly to Sinn Fein? And when is that likely to happen? Again Mr Trimble thinks it unhelpful to look at this in terms of a timetable. "There are a number of variables in this. We need to see how things evolve."

Seamus Mallon, for one, thinks the timetable clear and that the Executive in "shadow" form should be up-and-running within weeks.

Mr Trimble simply says: "This won't happen. The timetable isn't there."

The UUP leader's own projected timetable is clear. The week after the election the Assembly meets and appoints an interim presiding officer, and the First and Deputy First Ministers "designate". In addition to a Standing Orders Committee, Mr Trimble foresees a working party commencing a radical examination of the North's administration, how many departments there should be and so forth.

He insists ministerial portfolios cannot be distributed until this is settled and does not anticipate the appointment of the shadow Executive until around November. He is also adamant that the First and Deputy First Ministers can provide the necessary "coherence" and that the task of agreeing the shape and nature of cross-border implementation bodies can be completed by the end of October without the appointment of shadow ministers.

Mr Trimble believes this is the best opportunity local parties will have to ensure that "radical shake up of the administration" at Stormont. He is worried lest they fall foul to the "yes minister syndrome" and leave it to the civil service "to have it all cut and dried".

And then there's also the human element. "There's another factor to be borne in mind. When we get to summer, there are going to be an awful lot of very tired people, myself included. So, basically, we come back in September and start work."

How will First Minister Trimble work with Deputy Hume or Mallon? Leaving personalities aside, he says: "The thing to bear in mind is that there would not have been an agreement without the Ulster Unionist Party and the SDLP . . . When it came to the bit in that week we actually worked together."

And how, I wonder, would First Minister Trimble get along with Secretary of State Mowlam? "Well again, I don't think it's wise to make assumptions," he replies, amid more laughter. Is that assumptions about his position or hers? Refusing again to get into the personality stuff, Mr Trimble agrees this will be an important aspect of the new dispensation, and that there will be tensions about things like budgets "and the extent to which Westminster can pre-determine Northern Ireland policies".

One begins to sense that the "yes minister syndrome" is about to take on a whole new dimension - that if the UUP doesn't quite know what has hit it yet, the Northern Ireland civil service may not have grasped what lies just around the corner.

And, finally, can David Trimble envisage the day when Minister Adams welcomes First Minister Trimble to his West Belfast constituency?

This time there is no hesitation, save for the insistence that he is taking nothing for granted. "Were I in that position . . . I am looking forward to visits to west Belfast, were west Belfast is not terra incognita for me."

For all the caveats, get-out clauses and undoubted problems to come, the unmistakable impression talking to him is that Mr Trimble knows exactly where he is going. Thursday will tell if he can bring his people with him.