Any failure by the UVF and the UDA to respond broadly along the lines of the IRA's commitment to "completely and verifiably" put its arms beyond use could threaten the overall agreement hammered out by the two governments, the IRA, Sinn Fein, the UUP and the SDLP over Thursday and Friday.
The initial response of the political representatives of the UDA was quite negative, while those representing the views of the UVF were guardedly optimistic that this time politics is back on track, and that the paramilitaries could fade into the background.
Spokesmen for the Ulster Democratic Party, which is linked to the UDA, and the Progressive Unionist Party, which is linked to the UVF, said they were not briefed about the details or the possibility of a breakthrough when they met the Taoiseach, Mr Ahern, and the British Prime Minister, Mr Blair, in Hillsborough on Thursday.
UDP leader Mr Gary McMichael said that based on his current assessment he could not recommend the deal to the UDA. However, Mr Billy Hutchinson, the PUP MLA and the UVF's interlocutor with Gen John de Chastelain's decommissioning body, was sanguine about the lack of information. He appeared more confident that the UVF might reciprocate the IRA statement.
The UDP is meeting today to consider its formal response. Mr McMichael said he was annoyed he was not fully briefed on developments as they unfolded. "We had repeatedly warned the two governments that loyalists should not be isolated from the process, and that we could not sell any proposals if we were not part of the negotiations."
Mr McMichael expressed his frustration in telephone conversations on Saturday with Mr Ahern and the Northern Secretary, Mr Peter Mandelson. He is also seeking a meeting with the UUP leader, Mr David Trimble, to hear his assessment of the IRA's intentions.
Mr McMichael said he had serious concerns about the bona fides of the IRA statement. He feared the pledge to initiate a process to put its arms "beyond use" was in reality only a statement that IRA arms were not being used at any particular time they were being examined by independent inspectors.
The UDP said there was nothing in the statement to express "finality" about the IRA's campaign of violence. He said, however, he was willing to be convinced that this was indeed a genuine offer that deserved an equally positive response.
Failure by either the UDA or the UVF to respond positively could threaten the deal. The IRA is unlikely to put its arsenals fully beyond use if the main loyalist organisations don't respond with an equivalent gesture.
Mr McMichael left it clear that the British government in particular must engage in some serious conciliatory work to ensure that the UDP and UDA come on board.
Mr Hutchinson expressed more minor irritation that they were not central to the main negotiations. However, he said if the UUP and Sinn Fein had genuinely resolved their differences and come up with a workable formula on arms, he expected the UVF would also be satisfied.