Will it be a stalking horse or a pantomime donkey? That's a question exercising anti-agreement unionists as they consider a direct challenge to David Trimble's leadership at the annual meeting of the Ulster Unionist Council on Saturday week.
Some of Mr Trimble's most implacable opponents are determined a challenge there will be. Councillor Jonathan Bell from Craigavon confirms he might enter the fray, while suggesting that the figure who eventually emerges might not be seen at all in the "stalking horse" category.
Since Mr Bell presumably does not think himself a potential leader, this reflects the ongoing speculation that Mr Trimble might ultimately be opposed by someone from the party's "mainstream". Sources close to Mr William Ross rule nothing in or out at this stage, although some who might be expected to support the East Derry MP say they would be surprised if the challenge comes from within the parliamentary party.
Behind the uncertainty lie serious, and as yet unanswered questions, about the nature and purpose of the proposed challenge. In general terms the intention may be plain enough. However, as pro- and anti-Trimbleites both observe, the current situation in the UUP is not comparable with that in which Sir Anthony Meyer ran against Margaret Thatcher, or the then Queen's University student Lee Reynolds opposed Jim Molyneaux.
With Thatcher and Molyneaux it was a case of long-established and successful leaderships which had not previously been challenged or considered under threat. The point of the stalking horses, Meyer and Reynolds, was their ability, despite their patent lack of credibility as leadership contenders, to attract sufficient support to destabilise their respective leaders. For both Thatcher and Molyneaux, the stalking horse challenges marked the beginning of the end.
But as one Trimbleista observes, a stalking horse challenge to him will confirm only what is already known - that the UUP is split down the middle and Mr Trimble's leadership grip already tenuous. Moreover, the fear nagging some would-be plotters is that a challenge at this point could actually alienate party members averse to public displays of disunity and so badly backfire. The fear is nourished by the suspicion that Mr Trimble might actually relish a sham fight and emerge the stronger from it.
One possible successor to Mr Trimble concedes there is not, as of now, a UUP majority for unseating the leader. "The real anti-Trimble faction probably accounts for a third of the party," he says. "But there are many middle of the road people who joined us last November to vote against going into the executive because they thought Trimble had conceded too much ground over decommissioning. Those people are probably content that the executive has been suspended, and they certainly won't be voting to kick him out while he holds to his present position."
Others on the party's right wing, while bitterly opposed to Trimble, also evince contentment that he is now the effective prisoner of the Ulster Unionist Council, and that they can consequently play a waiting game. They also think they might not be waiting long.
Politics is a rough old trade, and the calculation is made with brutal directness. Either Mr Trimble holds to his present line and eventually loses his utility as far as both governments, the SDLP and Sinn Fein are concerned - or he is tempted back into the executive with no IRA guns on the table, and loses his party. Some of his opponents regard it as a safe each-way bet: if Mr Trimble is unable to advance the political process and thus save the Belfast Agreement, they reckon he will eventually question the point of his continued leadership and simply walk away.
Suspicions are running high that some of those closest to Mr Trimble are desperately seeking an alternative to the "no guns, no government" policy. And the pro-agreement camp itself is split between those who believe they should stick to the current high moral ground - and those exploring an alternative context in which to address the arms issue.
Mr Trimble has assured senior colleagues no serious business will be conducted this week in the United States. However, suspicions have been fuelled by the Taoiseach's throwaway line about expecting no real progress until after the UUC's annual meeting - and by indications that the British government now shares Dublin's hope to have the executive reinstated as early as next month.
The basis of this renewed optimism apparently is the prospect of an IRA statement confirming, in terms, that the war is over and that its commitment is to disbandment, and indicating the circumstances in which it would put its weapons beyond use.
If a possibility of this kind is being signalled by the republican leadership - and is not simply an Irish Government fiction - then clearly Mr Trimble will want to explore it. However, some of his most loyal supporters think it the stuff of political fantasy.
It is not hard to see why. The IRA refused to start decommissioning in order to avert the suspension of the executive, despite the exhortations of the British, Irish and US governments, and of Mr John Hume. Had it answered his call, and decommissioned some semtex, it could have delivered maximum advantage to Mr Adams, liberated Mr Trimble, and devastated the unionist "rejectionists".
Is there any basis for thinking that the republican movement is now ready to replace decommissioning with disbandment? Free of caveats and conditions about the "removal of the causes of conflict" in Ireland? To a precise timetable, albeit of its own stipulation? And can there, anyway, be true disbandment without a resolution of the other "D" word?
For as far as many in the Ulster Unionist Party are concerned, all roads lead back inevitably to decommissioning. Until now it has seemed clear that, whatever creature might stalk him on Saturday week, the real moment of truth - for Mr Trimble and his party - would come if and when he chose to take another route.
Yet we might be looking in the wrong place. At this writing, senior party officers were beginning to think that the real Trojan Horse might be the policy proposal to link any return to the executive to the rentention of the RUC's royal title. The Ulster Unionist Party's Glengall Street headquarters awaits the formal requisition from Mr David Burnside, the London-based businessman, requesting a second, emergency meeting of the UUC. He has formally notified it in accordance with the party's rules and the motion, with the necessary 60 signatures, will be submitted today or tomorrow.
One option being considered last night was to hold the emergency meeting immediately after the a.g.m. on March 25th. But the real nightmare for Mr Trimble will be finding a way to persuade his party to reject a motion which all its instinct and emotion will urge it to support.
Mr Burnside's motion is no pantomime donkey.