The SDLP deputy leader, Mr Seamus Mallon, insisted yesterday that preserving the morality and political imperative of the multiparty talks were essential elements in deciding Sinn Fein's fate at the table.
With that decision set to dominate proceedings when the talks resume at Dublin Castle this morning, Mr Mallon made explicit that the "dilemma" facing the participants rested on ensuring the will to find a settlement was not lost while at the same time preserving the morality of the talks.
Mr Mallon said it was for the two governments to provide the evidence that Sinn Fein had "demonstrably" failed the test of the Mitchell Principles in the light of the RUC's assessment that the IRA was responsible for the killing of two men in Belfast last week.
Using the strongest terms yet, Mr Mallon told the BBC programme On the Record the parties must ensure the political imperative did not become "political expediency . . . because without it then we're into a quagmire of expediencies which will not further the cause of getting a settlement". The parties would be "guided" by the two governments, he said, and a decision on the evidence would be made according to the rules of procedure governing the talks.
Insisting that the search for a political settlement was paramount, Mr Mallon said there were two issues at stake. "One is the moral core of the political process and these negotiations which have got to be protected; the other is the political imperative to try and get a political settlement which is as inclusive as possible."
If the evidence showed that Sinn Fein must be expelled, then the political parties must be prepared to display the "courage" to "do the proper thing, we have got to do the right thing. If that proper thing and the right thing takes a certain amount of courage then we'll have to show that courage."
When pressed on what position the SDLP would adopt in the face of demonstrable evidence that Sinn Fein had broken the Mitchell Principles, Mr Mallon said he did not wish to prejudge the evidence either way, but he was not prepared to allow men of violence derail the talks. Sinn Fein must disavow murder and disown the IRA in such a way that demonstrated their preference for the political process rather than their links with a terrorist organisation, he said.
The two governments must also come up with an "end paper" or "global overview" of what a final settlement might consist of in order to refocus the whole talks process.
On the same programme, Sinn Fein's chief negotiator, Mr Martin McGuinness, categorically denied there was any case for excluding the party from the talks.
Claiming that Sinn Fein had not broken the Mitchell Principles and that the party was not linked to any paramilitary group, Mr McGuinness warned of a conspiracy to keep the party out of the talks.
While not predicting the end of the IRA's ceasefire in the event of Sinn Fein's expulsion, Mr McGuinness said "circumstances on the ground" could conspire to prevent the party's re-entry to the talks and that there were many people who wanted to destroy the peace process.
When asked by the interviewer if he meant the IRA could go back to killing, Mr McGuinness said he was not saying that. "Any number of conspiracies could take place," he said.
Speaking later yesterday, Mr McGuinness said there was "no case whatsoever" for Sinn Fein to be put out of the talks. He said the party would be demanding that the British government "put on the table the evidence which they say will lead to Sinn Fein being excluded". It would be "a grave injustice" if the party were expelled. Mr McGuinness said the Sinn Fein president, Mr Gerry Adams, had "completely disavowed all killings". Sinn Fein had no connection with the killing of anyone. "We don't speak for the IRA. The only people we represent are those people who voted for us." Sinn Fein was a completely separate, distinct organisation with "no organic links whatsoever to the IRA".
Describing the RUC as "a paramilitary force working on behalf of unionism and the British government", he said: "Let us not take decisions on the back of a so-called assessment by the RUC Chief Constable, a force which is prejudiced against Irish republicans."