The Taoiseach, Mr Ahern, and British Prime Minister, Mr Tony Blair, arrive in Hillsborough this morning seeking endorsement by pro-Belfast Agreement parties of a package that requires the IRA to demonstrate its "war is over".
A blueprint for agreement could be presented later today, according to one British insider, who added that, while serious difficulties remained to be resolved, a deal was still possible.
"Positive messages are coming from Sinn Féin, the Ulster Unionists, and all the main players. While we don't underestimate the problems, we believe the gaps can be bridged," he said.
The bottom line for the British and Irish governments is that the IRA illustrate it is effectively standing down and, if such a radical pledge is forthcoming, that UUP leader Mr David Trimble will make a solemn commitment to share power with Sinn Féin.
Mr Ahern and Mr Blair have put together the main elements of an agreement to present to the parties but, because of loose strands that have the potential to unravel the chances of a deal, may not formally table their proposals when they first gather at Hillsborough Castle this morning, according to Dublin and London sources.
The main elements of what Mr Ahern and Mr Blair believe will allow the restoration of devolution are:
- The IRA to verifiably end all activity backed by major and swift act or acts of decommissioning to convince unionists of republican bona fides.
- The British army, over a three-year period, to demilitarise all its watchtowers in south Armagh and along the Border, and to reduce troop numbers to pre-Troubles figures.
- A British government commitment to devolve responsibility for criminal justice and police to the Northern Executive, but over a two-year period.
- Sinn Féin to join Policing Board.
IRA fugitives, or "on the runs" to be allowed to return to the North but must first go though judicial process.
- British government to suspend legislation permitting it to unilaterally suspend operations of Executive and Assembly.
It is not clear if the IRA will fully meet the demand to end all activity. Sinn Féin chief negotiator Mr Martin McGuinness was relatively positive when he addressed republicans in south Armagh yesterday. Today's talks would be "absolutely critical to the future of this entire island", he said.
"We say to the leadership of the Ulster Unionist Party there is an opportunity here to move forward," Mr McGuinness added.
Sinn Féin and the Ulster Unionists have adopted polarised positions on the sanctions issue, which has the potential to wreck the chances of agreement. Mr Trimble insisted there must be a graduated system of penalties that could be imposed against Sinn Féin, up to exclusion of its ministers from government if the IRA deviated from any commitment that its "war is over".
"Without this sort of guarantee there won't be any progress," he insisted on BBC's Politics Show yesterday. Mr Gerry Adams and Mr McGuinness in statements said that, "under no circumstances, will Sinn Féin accept the rights of our electorate being diluted or denied".
The Government will have to pass legislation in the Dáil to cope with covering "on the runs" - although Dublin sources said there was no question of an amnesty. Special legal arrangements will be made to ensure those affected will not serve time in jail.
People who fail to come forward will be subject to prosecution. "They would still be covered by the Good Friday agreement, but they would not be dealt with quickly.
"They would have to spend time in jail if they were refused bail. So there would be encouragement to them to deal with it now," one source close to the talks told The Irish Times.
Some senior pro-Agreement unionists are suggesting Mr Trimble could use changed electoral rules to prevent party dissidents contesting fresh Assembly elections under the Ulster Unionist banner.
This was confirmed amid a growing sense in unionist circles that Mr Trimble believes "on balance" that an agreement can be reached on acts of IRA and British "completion", paving the way for the return of devolved government.
