When David Trimble rises from his seat at about 11.15 a.m. tomorrow to deliver the keynote speech to the Ulster Unionist Party delegates, many in the audience will be wondering if this will be his last party conference as leader.

He has displayed a chipper front this week. Don't write any obituaries, he warned, either for him or for the Belfast Agreement. It is too early to write "finis", he said on Wednesday. The great interlocking drama of Mr Trimble's and the Good Friday accord's future is still unfolding.

Tomorrow at the Killyhevlin Hotel in Enniskillen, Co Fermanagh, the delegates will be split into three factions: the pro- and anti-agreement blocs, and the ditherers.

This UUP annual conference will allow the public an insight into the mood of mainstream, or "middle-Ulster", unionism. But Mr Trimble already knows the mood of the members. It ranges from a nervous wish to take some risks (the Yes side) to a truculent attempt to manacle Mr Trimble to the concept of guns before government (the No side) to a state of desperation and political fatigue (the ditherers).

We should hear a stout defence of the agreement from Mr Trimble, together with an insistence that its implementation depends on an IRA commitment to disarm.

However, it is unlikely we will hear from him tomorrow exactly what he proposes to do when, in the next couple of weeks, Senator George Mitchell lays it on the line for the parties to his review to do a deal, or to walk away from the agreement. In fact, it is crucial to the agreement that we don't hear his real plans for the rest of the review.

He will hold to the position of "no guns, no government" while, probably implicitly, leaving open the option of sequencing; the North's shorthand for Sinn Fein taking seats in an executive based on an IRA commitment to disarm, a commitment to be speedily delivered.

The conference programme is carefully crafted by Mr Trimble and the party's senior officers. There is an element of stage-management to prevent anything critical of his leadership appearing on the official agenda. However, that won't prevent anti-agreement delegates attempting to tie him down to a policy of demanding prior IRA disarmament.

The two main motions effectively deal with the Mitchell review and the Patten report. There could be criticism of the leadership during the discussion of the Patten recommendations as the report was a byproduct of the Belfast Agreement, endorsed by Mr Trimble.

Nonetheless, there is a unity of purpose across most of the UUP in opposition to the proposals on police reform, particularly those relating to culture, ethos and symbols. Mr Trimble and those loyal to him should be able to ride any attacks here.

The political development motion calls for republican and loyalist disarmament. If that is not delivered then the UUP and the SDLP should abandon Sinn Fein and form the executive with the other "constitutional" parties, it effectively states.

Opponents of the agreement will be able to table amendments to this motion seeking to restrict Mr Trimble's capacity for movement. It will be vital for Mr Trimble that he has room to manoeuvre in this final phase of the review. The test here for the pro-agreement side is to ensure that, while adhering to the principle of IRA decommissioning, it will be for Mr Trimble and his team of negotiators to decide in the review how to achieve that goal.

If Mr Trimble is allowed a free hand there will be still some hope for the Belfast Agreement. It will prove that the risk-takers could yet win the day. If it goes the other way it could be ominous for the rest of the process. A lot hangs on whether this motion can be passed without serious amendment.

The likes of Mr Jeffrey Donaldson, Mr William Thompson and Mr William Ross, the Union First Group and the sharp-suited Young Unionist Council may try to make life difficult for their leader tomorrow. The Strangford MP, Mr John Taylor, believes the agreement is a lost cause. He says it may remain on life-support to the end of October or mid-November but then Senator Mitchell will flick the "off" switch and return defeated to the US.

Quite a number in Enniskillen tomorrow will agree with that analysis or wish that it proves correct. But so far the people who count, his Assembly team - apart from Mr Peter Weir and Mr Taylor - have still not defected to the No side.

Observers will be monitoring tomorrow's rostrum comments of the Assembly members, particularly those such as Mr Roy Beggs jnr and Ms Pauline Armitage, who are viewed as very shaky on the agreement. It will also be enlightening to hear the views of two Assembly members, Mr Duncan Shipley Dalton and Dr Esmond Birnie, who are risk-takers.

Mr Shipley Dalton has already been severely criticised for suggesting that the UUP in July should have tested whether the IRA was serious about disarmament by forming the executive. Now Dr Birnie, a Queen's University academic colleague of Mr Trimble's, has floated a fairly radical idea of the UUP sitting in government with Sinn Fein without IRA decommissioning but on the basis of a guarantee that Sinn Fein would resign its seats if the IRA did not subsequently deliver.

Mr Shipley Dalton and Dr Birnie may serve a useful purpose in deflecting some of the anti-agreement heat from Mr Trimble on to themselves. Dr Birnie insists, perhaps too strongly, that his proposal is a personal view but one wonders if he would float such a concept without at least a nod from Mr Trimble.

His idea is interesting, but probably would not work. However, it may signify a straw in the wind, a suggestion that come the final week of the review Mr Trimble may yet devise imaginative ideas - perhaps a variation of Dr Birnie's - which might trigger a positive response from Mr Gerry Adams and Mr Martin McGuinness.

The Assembly team, uncharacteristically, has remained tight-lipped about its recent get-together in Glasgow. Word from some sources is that while Mr Trimble did not put particular proposals he did metaphorically bring the politicians to the precipice and show them what lay ahead if the agreement collapsed.

The 500 or so delegates may hear more apocalyptic visions of what failure could bring when, in a conference innovation, they will be treated to the opinions of journalists and commentators such as Eoghan Harris, Ruth Dudley Edwards and Eamon Mallie.

Mr Trimble, going into the conference, has received no favours from Messrs Adams and McGuinness. Recently, Mr Adams demanded that the UUP leader face down the anti-agreement "rejectionists" in his party. Sinn Fein regularly complains that Mr Trimble will condemn republican violence but turns a blind eye to the activities of loyalist paramilitaries.

What did Mr Trimble do? Last week he delivered an amazing tongue-lashing to the Young Unionists for their anti-agreement stance, and called a special press conference to specifically denounce loyalist violence. (Both Sinn Fein and the UUP denied that there was any inter-party choreography in this, but then they would, wouldn't they? Another straw in the wind?). But still there was no reciprocation from Sinn Fein. Maybe that's for another day?

What's vital for Mr Trimble tomorrow is to emerge unshackled to the wishes of the No bloc. This at least leaves some hope of the review succeeding. It won't be an easy gig, but there's still fighting spirit in Mr Trimble. The situation - to quote an old Irish political proverb - remains the same within the political process, the review, the agreement and within the UUP: desperate but not (yet) serious.