Former Northern talks chairman Senator George Mitchell has been invited to take part in a summit meeting on the peace process between the Taoiseach and the British Prime Minister, due to take place in London on Tuesday.
A British government spokesman declined to comment on speculation that the senator may be asked to chair a proposed review of implementation of the Belfast Agreement.
The purpose of inviting Mr Mitchell was "to discuss what role he might play to take the parties forward", a Downing Street spokesman said. In a 15-minute phone conversation last night, the two leaders agreed the review would be "tightly focused" on the establishment of the executive and decommissioning.
The meeting could determine the fate of the process, plunged into crisis by yesterday's events in Belfast. While there were no indications that the two governments have a clearly worked-out strategy, nationalist sources in the peace process said last night that the proposed review must be seen as a speedy one.
This was echoed by senior sources in the Ulster Unionist Party who said: "We want this to be really speedy and put this thing back together again as quickly as possible."
The review would consider the implementation of the Belfast Agreement rather than the content, British government sources stressed. Already there have been signs of very adverse nationalist and republican reaction to suggestions that no fresh initiative in the peace process could be expected until October. This would cause problems for the Sinn Fein leadership which is already feeling internal criticism over its stance on decommissioning. There is also deep suspicion in republican circles that the unionists are intent on delaying the formation of the executive until May 2000.
Senior SDLP sources said the role of the two governments was now critical. "The ball is back in their court." Dublin and London would need to make clear that the review was a "serious" process which would start immediately.
Republican sources said it was essential that, despite the failure to establish the executive and the North-South ministerial council, the two governments should make clear that all other aspects of the Belfast Agreement would be fully and swiftly implemented. This was critical in preventing further erosion of confidence in the agreement within the republican community. Promised moves on demilitarisation, equality, human rights and policing must proceed apace.
Speculation continued about the position of Mr David Trimble as First Minister. Usually reliable sources said they expected him to step down within a week but this was denied in UUP circles who said this would be a blow to public confidence in the agreement.
Mr Seamus Mallon's resignation came as a surprise to the UUP leadership, according to senior sources, despite the fact that he had previously hinted publicly at such a move.
Mr Trimble would be obliged to step down as First Minister if the deputy's post remained vacant for six weeks. Last night, Mr John Taylor, the UUP deputy leader, said he believed Mr Trimble should continue in the post.
UUP sources said party strategy was to seek to have a deputy first minister, preferably Mr Mallon, back in place within that period. Other party sources urged Mr Trimble to stay on despite Mr Mallon's challenge, which they described as " a fit of pique."