Sinn Féin's chief negotiator Mr Martin McGuinness has indicated that any future IRA decommissioning would be more convincing for unionists notwithstanding a reportedly fractious meeting between the Sinn Féin and Ulster Unionist leaderships at the weekend.
Mr McGuinness and the Sinn Féin president, Mr Gerry Adams, expressed their opposition to a new Ulster Unionist resolution on the joint declaration when they met the UUP leader, Mr David Trimble, on Saturday, according to reliable sources.
Mr Adams and Mr McGuinness were annoyed at the motion adopted by the UUP's 110-member executive on Friday calling for "radical change" to the Hillsborough declaration, and made their views known in strong terms to Mr Trimble and former UUP minister Mr Michael McGimpsey, the sources said.
"There was a bit of a barney before they moved on to other matters," explained one insider.
Anti-Belfast Agreement elements within the UUP have sought to characterise the motion as an outright rejection of the declaration. Supporters of Mr Trimble, however, have stressed that the motion does not reject the declaration, adding that IRA acts of completion would transform "the political context".
Mr Trimble himself on Friday described the motion as "nuanced".
"The situation was explained to Gerry Adams and Martin McGuinness on Saturday. At the end of the day, it's a phoney war over the resolution. If and when we get IRA acts of completion then the situation will inevitably change," said one senior source.
The British and Irish governments are also sanguine about the UUP motion. Dublin and London sources told The Irish Times they were not surprised Mr Trimble would firm up the party's position on the declaration in the absence of the IRA effectively stating that its war is over.
Republicans, however, insist that the resolution has made it "much, much more difficult" to achieve a successful outcome to the intensive negotiations aimed at restoring devolution, primarily involving the two governments, Sinn Féin and the UUP.
One Sinn Féin source said the motion raised question marks over whether Mr Trimble would be able to guarantee that he would work the institutions of the Belfast Agreement in the event of movement from the IRA.
"This has caused very serious concern and sent waves of nervousness through republican and nationalist ranks," he said.
The same source said that Saturday's meeting ended on a cordial note, and that both sides agreed to say that it was "useful".
More meetings involving the Sinn Féin and UUP leaderships are planned for the coming days. The parties are also in contact with the two governments.
A key element of any deal is almost certain to involve a third act of IRA decommissioning. However, because there was such little detail from Gen John de Chastelain's decommissioning body about the last two IRA acts of disarmament, unionists, both pro- and anti-agreement, were highly sceptical about the extent of the decommissioning.
Mr McGuinness, however, has acknowledged that this is a serious issue for unionists. "We are not immune to the arguments that are being made, but at the same time we are also conscious that there are people out there in the anti-agreement unionist side who, no matter what is said and done, will not be satisfied," he told BBC Radio Ulster's Inside Politics programme on Saturday.
