ULSTER PEACE TALKS: Stamina stretched to the limit, they could barely trust their own faculties

INSIDE HIS ministerial office on the top floor of Castle Buildings, Tony Blair was sure he could glimpse a movement in the political landscape. As David Trimble, the Ulster Unionist leader, and Gerry Adams, president of Sinn Fein, shuttled back and forth from their rooms on the floor below, the Prime Minister was convinced that the republicans had moved far enough to clinch a deal. His only problem was to convince the Unionists.

"He believed Sinn Fein were genuine in their promise to try to secure full decommissioning of weapons by May 2000," said one of his spokesmen. "When Gerry Adams said it was not in his power to deliver more, the Prime Minister believed him.

"When David Trimble said that was not a position that went far enough for his people, he believed him. The problem was, the two sides didn't believe each other."

It was mid-afternoon yesterday when Mr Blair, clearly exhausted after two physically and emotionally draining days, was holding round-table talks with representatives of all the parties involved. For many of the smaller groupings, such as the Alliance Party, the Women's Coalition, the UK Unionist Party and the Northern Ireland Unionist Party, it was the closest they had been to real talks. Mostly, like the rest of us, they had been hanging around drinking coffee.

Mr Blair and his Irish counterpart, Bertie Ahern, had been at the sharp end of negotiations since shortly after 9am on Wednesday. By last night, Mr Blair had held almost 100 meetings. His stamina was being stretched to the limit: Wednesday's talks, after passing the officially agreed midnight deadline, had not been adjourned until 4am yesterday.

The discussions took place at a nondescript office block used by the Department of Health and Social Security in the grounds of the Stormont estate. Depending on which side of the building you viewed his office from, the Prime Minister was on the second or fourth floor. In between high-pressure meetings, he and Jonathan Powell, his chief of staff, had a view over drab office buildings and then, in the distance, swaths of pleasant greenery.

Mr Ahern had an office on the same level, while below them were rooms occupied by Mr Trimble, Mr Adams and their teams of negotiators. On the wall of Mr Adams' room sat a picture of the republican hunger striker, Bobby Sands.

Mr Blair was convinced that he could close the gap between the parties and, in separate meetings with Mr Trimble and Mr Adams in his office, he told them so. However, Sinn Fein's "seismic shift" appeared to have wrong-footed Mr Trimble.

A representative of one Unionist party with close ties to a paramilitary group said Sinn Fein was offering "aspirations" that it could persuade the IRA to give up its weapons by May 2000. But there was nothing in writing, no promises.

"The problem for David was that we had been saying for the past year that Adams and Martin McGuinness were members of the IRA's army council - so talking to them was like talking to the IRA," he said. "It was difficult to accuse them of being on the army council while saying that their `aspirations' carried no weight."

Inside the building, nerves were becoming frayed. Most of the representatives - at times numbering somewhere in the region of 100 - had no idea what was going on.

"Ninety per cent of the people in there are doing absolutely nothing except sitting in the bar or restaurant," said Bob McCartney, UK Unionist Party MP for North Down. "There are five negotiators for the Ulster Unionists and a similar number with Sinn Fein, and there is Blair and Ahern. They say we are supposed to be kept informed, but we aren't."

Instead, the surplus numbers kept themselves entertained by listening to the rumour mill or enjoying the restaurant menu of soup, smoked salmon, roast chicken and beef stroganoff.

"Blair was the only person who didn't move office," said one Sinn Fein representative. "Everyone else shuffled to him. In addition to the formal meetings, there were informal talks. You found yourself moving from room to room - it wasn't very structured. You were meeting people in the corridors, talking to them, chatting and explaining things. But wherever we were, we always assumed we were being bugged. We knew that and factored it in."

By late afternoon, even Mo Mowlam, the Secretary of State for Northern Ireland, appeared exasperated. She left the talks to answer weekly questions on Northern Ireland in the House of Commons.

She told MPs: "At lunchtime, we were feeling positive. By the time I left to come here one hour later, people were getting worried again. It goes up and down, three steps forward and two steps back."

Slightly more than an hour before Wednesday night's deadline, Gerry Adams appeared unexpectedly to give hundreds of waiting journalists a briefing. Looking calm, fresh and neat, he insisted Sinn Fein had shifted its position - taken to be its movement on decommissioning - and was waiting for the Unionists to have the courage to jump together into the future. He had clearly decided to take the initiative.

Within minutes, Mr Trimble appeared to say there had been continued intransigence on the part of Sinn Fein on decommissioning. However, when pressed by journalists to confirm that he had had an improved offer from Mr Adams, he insisted he had so far had nothing in writing.

Seizing on the nuance, journalists pressed him again. Had there been anything verbal? An indication that Sinn Fein really meant business? He became flustered and marched off without giving a full reply.

Pessimism and desperation descended, but within half an hour there was talk of renewed hope. The report by General John de Chastelain into the paramilitary groups' willingness to disarm would be published within the hour. This had been held back for two days, a move taken by the Unionists to mean that he had found an unwillingness on the part of republican groups.

Secondly, news filtered through that Mr Adams and Mr Trimble had held "several" face-to-face meetings and that Mr Adams had offered to speak to all Unionist Assembly members. The signs were good.

However, the deadline came and went, the rollercoaster hurtled into another trough and, by 4am, the talks were adjourned. One government spokesman said that the representatives were so exhausted by this stage that they did not trust their own faculties for decision-making.

Across the Atlantic, the American President, Bill Clinton, had been kept informed of events. He made two 10-minute calls to Mr Blair, offering to intervene if requested, and then called Mr Trimble and Mr Adams on his return to Washington from a fund-raising dinner in Chicago aboard Airforce One.

"The President made the point to both of them that they need to stay the course and resolve this, because it's too late to turn back now," said Joe Lockhart, the White House spokesman.

Frustrated, Mr Blair and Mr Ahern retired for the night to Hillsborough.

The talks resumed yesterday shortly after 1pm. Gerry Adams and Martin McGuinness arrived at 12.30pm and immediately went on the offensive. Mr Adams believed he had taken a big political risk the day before and he had told Mr Blair and Mr Trimble he would need something to show for his movement.

Now, he said, after reading of his rejected offer, his supporters were beginning to ask some tough questions.