There was a guarded expectation in Dublin, London and Northern political circles last night that the breakthrough necessary to anchor the institutions of the Belfast Agreement could happen within the next seven days.
Sinn Fein, however, warned against over-optimism, saying there were still serious obstacles to be overcome before it could sign up to the police reform package.
The Taoiseach, Mr Ahern, is to meet the British Prime Minister, Mr Tony Blair, in Downing Street on Wednesday to try to resolve the outstanding problems around the issues of policing, demilitarisation and paramilitary arms disposal. The new Northern Secretary, Dr John Reid, is holding talks with the North's parties today, including anti-agreement groupings.
Mr Blair and Mr Ahern may return to Northern Ireland later in the week if they believe a settlement can be finalised. "It is true that we have made progress," Mr Ahern said on RTE yesterday. "It is unlikely that we will get a substantive breakthrough unless we get progress across all fronts," he added.
Senior British, Irish, Ulster Unionist and SDLP politicians and sources agreed that a deal was close, but they all added the rider that more work needed to be done. Mr Ahern placed emphasis on his meeting with Mr Blair by describing it as a "summit".
The London meeting is generally being viewed as significant. "The fact that Bertie Ahern will be there is a clear signal that progress has been made. If things go well on Wednesday night, you could see them back in Northern Ireland later in the week," said one Dublin insider.
"Things are definitely more positive than negative, but there is always the danger of over-egging the chances of a deal," said a London source.
A senior SDLP figure said he believed its outstanding policing demands on issues such as inquiries, the closure of Gough barracks and the RUC Special Branch would be met by the British government. He also expressed some confidence that the gap between Sinn Fein and the IRA and the British side on demilitarisation and putting arms beyond use was narrowing.
There is speculation that the British army would accept the incremental dismantling of its south Armagh watchtowers based on serious IRA re-engagement with the decommissioning body and guarantees that the IRA would concrete over or otherwise render arms dumps inaccessible.
The Ulster Unionist leader, Mr David Trimble, told the BBC of efforts to get movement on IRA arms. He also said he hoped that policing could be "sorted out without too much controversy".
Mr Trimble and the SDLP Deputy First Minister, Mr Seamus Mallon, are due to be in France and Germany on a jobs-promotion drive until the end of the week, but they have indicated they would cut short their trip if there was a serious prospect of a breakthrough.
The most downbeat assessment, however, came from Sinn Fein. It expressed special annoyance at Mr Trimble's remarks. "David Trimble's comments on the issue of arms bear no relationship to the discussions in which Sinn Fein is involved," said the party's mayor of Sligo, Mr Sean McManus.
Reacting to Mr Trimble's comments yesterday, Mr Martin McGuinness of Sinn Fein said he did not know on what the Ulster Unionist leader had based his comments.
"You need to ask David Trimble that," he said. "As far as we are concerned, the big issue within this process is the issue of policing. That is the one that we have to get right.
"As far as the leadership of Sinn Fein is concerned, we want to see whether or not the British Prime Minister, who gave us his solemn word in May of last year at Hillsborough Castle, is going to at long last fulfil the promises and the commitments that he made. If he does that, then I think we can move on to resolve David Trimble's problem."