The Taoiseach, Mr Ahern has confirmed an IRA representative has met the head of the Independent International Commission on Decommissioning, General John de Chastelain.
The news will fuel expectation that the IRA is preparing to make a major statement on decommissioning in the next 24 hours.
The question of IRA weapons is central to prospects for the proposals put forward by Mr Ahern, and British Prime Minister Tony Blair, which would see the Democratic Unionist Party and Sinn Féin sitting together in the Stormont Executive.
The Taoiseach told the Dáil today he expects to know by this evening whether or not the proposals will be accepted. "Later this evening we expect to be advised finally whether we have agreement," he said. "If there is agreement we expect that this will be revealed tomorrow."
Mr Ahern told the Dáil that the talks between the IRA and General De Chastelain were ongoing. He did not specify when the initial meeting took place. However, he admitted that the issue of transparency surrounding the full decommissioning of all IRA arms was causing serious problems.
"There is one major difficulty and I don't see the resolution in that quite frankly," he said. "There are a number of issues which have not been resolved, though progress has been made and there are obvious technical issues that have to be dealt with."
He said it was "all or nothing" if a deal was not reached. "The Irish government has taken a middle view (on transparency issues) which will become clear," he said. "But if it doesn't work this won't come around again for quite some considerable time. If it doesn't work in the next 48 hours or less we are in a very difficult position."
Mr Ahern earlier confirmed he and Mr Blair would travel to Belfast tomorrow regardless of the response or lack of response from the two main parties. If a deal is not agreed, they intend to make public the details of the blueprint they offered to the parties.
The issue of visual and public confirmation of decommissioning is central to DUP leader Rev Ian Paisley's acceptance of any agreement.
Dr Paisley met Mr Blair in Downing Street yesterday. Following the talks, he insisted Northern Ireland had to be "free from the scourge of terrorism" and that the IRA must hand in its weapons before a deal was reached.
He said the IRA must accept his demand for the publication of photographs proving the complete decommissioning of its weapons arsenal if it wants power-sharing restored.
A senior DUP delegation met Gen de Chastelain's decommissioning body on Saturday. They complained after the meeting that the IRA had not yet renewed contact with the general.
Ulster Unionist leader Mr David Trimble held talks with Mr Blair at Downing Street this morning. Speaking after the hour-long meeting, Mr Trimble predicted "significant developments tomorrow" but said he agreed with the DUP that the verifiabiliy of any IRA decommissioning was essential.
"The crucial thing is there is transparency and that confidence is created and I think the parties need to sort this out," he said. "What is absolutely essential is that decommissioning occurs and occurs completely and does so in a way that it creates the necessary public confidence."
The SDLP leader, Mr Mark Durkan, is also meeting members of the Independent Monitoring Commission in Belfast today.