Sinn FEIN and the Ulster Unionists remained "deadlocked" last night in the dispute over the RUC name change which is threatening to derail the weapons-beyond-use deal to restore the Northern Ireland Executive.
Senior Irish officials met their British counterparts at Downing Street yesterday afternoon, but left after several hours of negotiations with no apparent agreement in sight.
Ulster Unionist sources, meanwhile, predicted that the brinkmanship would go "right down to the wire", with the party leader, Mr David Trimble, having to decide by lunchtime today whether or not to call a special meeting of the ruling Ulster Unionist Council for tomorrow week.
Mr Trimble will meet his Assembly party and party officers before making a final decision. Failure to convene the UUC would threaten at least to postpone the plan by the British and Irish governments to have the power-sharing Executive reinstated on Monday, May 22nd.
The mood in the Glengall Street camp was gloomy last night, with Mr Trimble said to be convinced he could not carry the UUC on the IRA weapons deal without a significant concession on the RUC issue.
Central to Mr Trimble's calculations is the position of his deputy leader, Mr John Taylor, who has said he is now reserving his position on whether or not to recommend that the UUC accept the deal.
The UUP leadership believes it had an agreement with the British government on the form of title to be used in the forthcoming policing Bill effecting the Patten reforms. It is understood this would have described the newly-constituted force as "The Police Service of Northern Ireland (Incorporating the RUC)".
However, authoritative party sources have told The Irish Times that it was "not possible to pin it down precisely" before the Prime Minister, Mr Blair, concluded the negotiation on the weapons issue at Hillsborough.
Contrary to some unionist suggestions, Irish sources say that the Taoiseach, Mr Ahern, was not party to any agreement, while willing in principle to see some concession made to Mr Trimble.
It was confirmed last night that Sinn Fein is, as one source put it, "100 per cent adamant against any departure from Patten, and they have left everybody in no doubt about that". And there were unconfirmed suggestions that the IRA had threatened to withdraw its proposed confidence-building measure - the opening of a limited number of arms dumps to outside inspection - if the RUC name was retained in the formal title of the new police service.
Earlier yesterday Sinn Fein's chief negotiator, Mr Martin McGuinness, said it would be a "serious blunder" to dilute the Patten plan and suggested it was "inconceivable" that Mr Trimble would not proceed with his planned meeting of the UUC.
"The Ulster Unionist Party needs to recognise now that there has been a huge step forward made last week with the IRA announcement", Mr McGuinness said. "I'm waiting, like everybody else, to see whether or not the unionist leadership is going to call a meeting of the UUC and make it clear that they are going to advocate going back into the institutions under the terms of the agreement."
The British government appeared yesterday to have stepped back from plans to have the order lifting the suspension of the Executive debated by MPs next week and to proceed with the second reading of the policing Bill on May 23rd. However, a Northern Ireland Office spokesman insisted that no conclusions should be drawn from this except that work was "continuing".