A confirmation process is to be established to validate that the IRA is no longer engaged in paramilitary activity in the event of the expected major initiative from the IRA.
The system will play a key part in talks in Hillsborough on Wednesday between the British and Irish governments and the political parties which are aimed at restoring devolution to Northern Ireland before May.
However, Government sources have rejected suggestions that they will put a final package to the NI parties when they meet. "It is more about trying to figure out people's bottom lines: what they will accept, rather than what they want."
The confirmation system would also be used to confirm that the British government honours commitments to close British army bases and implement outstanding elements of the Patten Commission's policing reforms.
The corroboration process would be primarily about reassuring unionists that any IRA pledge to cease paramilitary activity would be properly assessed and authenticated, said one source. Equally, the confirmation system would serve to assure republicans "that the British were meeting their side of the bargain", the source added.
Details have not yet been worked out and it is unclear whether a corroboration commission would be established or whether it would have independent members.
Dublin, London and Washington remain optimistic that the IRA will make a substantial move shortly to demonstrate that it poses no threat to the peace process. They are concerned, however, that the Ulster Unionist leader, Mr David Trimble, would spurn an IRA gesture.
However, the Government does not expect the IRA to declare that it is standing down. "If words like that are used, then they won't happen. The trick is to get them to do that in effect in a way that can be checked. We hear from Martin McGuinness that the IRA will be prepared to make a 'corresponding and responsible reply' if the British move. But what does that mean?" a Foreign Affairs source told The Irish Times.
When Mr Trimble recently met the British Prime Minister, Mr Tony Blair, in Downing Street, he stressed that unionists required copper-fastened guarantees that the IRA was inactive.
The governments hope that a continuous monitoring and corroboration device to establish that the IRA was genuinely inactive would persuade Mr Trimble and most Ulster Unionists to sign up to a new deal to restore the Stormont institutions and to allow Assembly elections to take place on May 1st.
While there has been speculation of the IRA standing down or declaring that its war is over, the British and Irish governments are not overly concerned about what form of words it uses; but rather that it demonstrates that it is no longer engaged in "punishment" attacks, intelligence-gathering, targeting and other forms of paramilitary activity.
Neither the Taoiseach, Mr Ahern, nor Mr Blair is expecting any deal to emerge when they hold bilateral meetings with the political parties at Hillsborough on Wednesday.
In the period after Wednesday's meetings, behind-the-scenes negotiations will continue in earnest to draft a blueprint for agreement. After Wednesday, the next major public push by the two governments is not expected for a week or two, sources said.
Meanwhile, the Sinn Féin president, Mr Gerry Adams, told republican activists in Belfast on Saturday that the British government was pursuing a strategy whereby the survival of Mr Trimble as leader of the UUP was more important than the survival of the Belfast Agreement.
"The current crisis in the peace process is not about the IRA. Of course, the existence of the IRA is an affront to its enemies. But this process is about changing all that in a way which will bring an end to all the armed groups," Mr Adams said. "Can that be achieved by ganging up on republicans? Or making movement towards basic rights conditional on movement by the IRA? Or by punishing Sinn Féin voters and other citizens if the IRA doesn't comply with unionist demands?"
He added: "Our party will not dodge our responsibilities in the times ahead. There is no way forward except through negotiations. We are agents of change and our commitment is to play a full role..."