The Taoiseach and the British Prime Minister are to arrive at Hillsborough Castle this afternoon following an historic deal agreed by Sinn Féin and the UUP. This will lead to November Assembly elections, and the final implementation of the Belfast Agreement.
A frantic day of activity is due to start early this morning involving IRA decommissioning, and an IRA statement on its peaceful intentions.
In what will be a dramatic day, the Ulster Unionist Party will declare a commitment to work the institutions of the Belfast Agreement, there will be a British commitments on demilitarisation and an announcement by the British government of elections on Wednes- day, November 26th.
After the election announcement today, the Sinn Féin president, Mr Gerry Adams, is due to issue a statement saying words to the effect that republicans will pursue their ambitions by exclusively peaceful and democratic means.
An IRA statement is expected to follow endorsing these comments. The IRA will not specify what paramilitary activities it is ending, but sources said the Adams and IRA statements would be sufficient to convince the governments and the Ulster Unionists that it is winding down as a paramilitary force.
The full activation of the Independent Monitoring Commission, due at the end of November and which will check if paramilitaries are ceasing activity, is also a "critical factor" in persuading Mr David Trimble to accept this form of wording from republicans.
This additional check on whether the IRA is genuinely ending activity will provide him with additional ammunition in the face of the virtual certain rejection of the deal by anti-agreement unionists, they said.
It is understood that Mr Trimble has convened a meeting of his party officers for 8.30 a.m. today to seek their agreement to convene a meeting of the ruling Ulster Unionist Council on October 29th.
It is understood Gen John de Chastelain left Belfast last night to oversee a third act of IRA decommissioning. That decommissioning is due to be confirmed today both by Gen de Chastelain's decommissioning body and by the IRA.
The nature of that confirmation is the one remaining issue that could still jeopardise this all-embracing deal that has the potential to result in a functioning Executive after elections.
Sinn Féin in the negotiations refused a UUP request that a third party, whom unionists could trust, should be present to verify this disarmament.
Republicans, however, insisted that decommissioning was solely a matter between the decommissioning body and the IRA. Sinn Féin's Mr Martin McGuinness, however, has acknowledged that unionists had a serious credibility difficulty with the past two non-detailed decommissioning events, and indicated that this third act would prove more convincing for unionists.
"Our mood is guardedly optimistic, but if this IRA decommissioning isn't absolutely convincing then that could still cause problems," said one senior Ulster Unionist source.
Talks insiders said they hoped that Gen de Chastelain would be able to provide an inventory of what was being decommissioned. Informed sources said that the amount of arms and explosives put beyond use in this third act would be "significant and substantial".
If this final possible obstacle is overcome, Mr Trimble, either by way of statement or in an afternoon press conference, is then set to endorse the deal, and pledge that he will work to maintain the stability of the Executive, Assembly and the institutions of the Belfast Agreement, including the North-South element.
The deal will also deal with the related issue of Sinn Féin joining the Policing Board and Ulster Unionists agreeing to the devolution of responsibility for policing and criminal justice to the Executive.
Sources say that it will be "implicit" that over a two-year period this devolution will take place based on the IRA having carried out "acts of completion" and Sinn Féin endorsing the new policing dispensation.
Mr Ahern and Mr Tony Blair are scheduled to give a joint press conference at Hillsborough Castle in the afternoon, where they will urge the pro-agreement parties to unite behind the deal.
Mr Blair is also due to issue commitments about demilitarisation, human rights, equality issues and other matters.
"I think most people are pretty buoyed up by what has been achieved, certainly the governments are," said one British source.
Mr Ahern and Mr Blair were engaged last night in intensive telephone dialogue. Yesterday, Mr Ahern referred to a single stumbling block, but said the crucial issues were the "stability of institutions" and certainty that "we're at the end of the game on paramilitarism".
