There was a smack of firm and decisive leadership about David Trimble's behaviour at Stormont on Monday night that even his admirers - a select but enthusiastic band - had not been accustomed to seeing in the past.

He took his party by the scruff of the neck, beginning with a meeting of the Assembly team on Monday morning. "The implication was fairly strong that anyone abstaining or voting against would lose the whip," sources in the Assembly party said.

There were warnings but there was a fair amount of cajoling as well. Trimble supporters assured the doubters there was no question of going into government with Sinn Fein unless there was IRA decommissioning and that a veto could be exercised over any such development. People were asked to vote Yes for the party's sake and on the basis that the motion was not of any great significance anyway.

The Democratic Unionists have alleged bully-boy tactics, with Mr Ian Paisley Jnr, for example, claiming he saw one UUP waverer being "cornered like a rat" and being told "what way he would f...ing vote". The UUP's Mr John Taylor scornfully dismissed these allegations as typical of the DUP's form.

One leading dissident is understood to have received a message that his political life was over and his career dead. It certainly seems the atmosphere became somewhat heated, as evidenced by yesterday's resignation of South Antrim Assembly member Mr Duncan Shipley Dalton as deputy chief whip on the grounds that Mr Peter Weir should not just have lost the whip but his party membership as well.

Insiders were hopeful Mr Shipley Dalton would reconsider what was seen as a somewhat hasty decision.

In the end, Mr Weir was the only member to vote against his party's motion. Other potential dissidents toed the line. One of these was Mr Billy Armstrong, who was not prepared to say last night whether he would do the same in the next vote on February 15th. "Things could change," he said.

Likewise Mr Taylor, with his flair for political theatre, has refused to give a guarantee that he will vote the same way on February 15th as he did on Monday night. That would be a most serious development but some observers suspect the member for Strangford may be just teasing.

At 29 members each, the pro- and anti-agreement camps in the Assembly are equally balanced. Mr Trimble could lose five more votes and still secure the minimum 40 per cent of unionists required under the Assembly's rules for cross-community voting on major decisions.

Some battle-weary UUP dissidents were saying yesterday that further defections were neither likely nor logical. By voting for the Trimble-Mallon report on Monday, the party had committed itself to supporting a set of proposals on February 15th which had been agreed by the UUP in the first place anyway.

"It's not impossible others besides Peter Weir will vote No. Realistically, it's highly unlikely." Apart from other considerations, there was a high loyalty factor in the UUP. "We're a way of life - like Fianna Fail," quipped one senior member.

Other UUP dissidents took a different view. They felt Mr Trimble's protestations on decommissioning were wearing thin. The juggernaut which would land two Sinn Fein ministers in the cabinet room was now unstoppable and the best the UUP could hope for was to avoid getting the blame.

The party would then be faced with the "nuclear option", i.e. wrecking the process or accepting the inevitable and "taking a risk for peace" by entering government with Sinn Fein. Some Assembly members might realise this ahead of February 15th and vote accordingly.

However, the official UUP line remains very firmly one of refusing to sit down at the cabinet table with republicans unless there has been at least a symbolic destruction of weapons by the IRA. "We are not bellying-up on this one," I was told.

Hope that the Provisionals will "do the decent thing", fuelled by dubious media articles and reports, has not entirely evaporated in the unionist camp, but if it doesn't happen, what is unionism's plan B?

The shutters come down at this point and it is not entirely clear whether there is an alternative strategy or the UUP just hasn't thought that far ahead.

AT THE end of March, Mr Trimble faces a meeting of the 900-member Ulster Unionist Council, the party's supreme authority, which goes through the ritual of re-electing the leader every year.

The transfer of powers is due to take place some two weeks earlier, on March 10th. If all goes according to plan, he will have dropped the "designate" suffix from his title of First Minister and be in a position to present himself as the man who brought self-government back to Northern Ireland.

However, he has stressed repeatedly that he will not share power with Sinn Fein ministers unless the IRA disarms, but all the indications are that this is not going to happen for a long time. We are therefore on course for yet another crisis in the peace process, one more round of brinkmanship and possibly even further visits from Tony Blair and Bertie Ahern, not to mention phone calls from Mr Clinton, if he still happens to be President.

Seasoned observers believe that the only realistic hope the UUP has of keeping Sinn Fein out of government is a renewal of IRA bombing and killing. A senior peace process insider said the continuing paramilitary beatings and shootings was doing "enormous damage" to main stream republicans and loyalists by undermining the claim of their political associates to be committed to the democratic process.

Northern Ireland has seen some fraught periods in its history. The next few weeks could be as challenging as any of them.