The leader of the Ulster Unionist Party, Mr David Trimble, has warned that if the IRA does not begin disarming, no UUP member will stand for election to the Executive and the North's political crisis will deepen.
On the eve of the publication of the two governments' blueprint for progress, Mr Trimble said that the contents of the document would be meaningless without movement by the IRA on decommissioning.
"It doesn't matter what is in any paper that is produced", he said. "The question is what is going to happen. And if there isn't satisfactory action on the ground, then no Ulster Unionist will offer himself for election as First Minister."
Without UUP participation in the election for First Minister, the Assembly would have to be dissolved. "That means that the crisis in the system will deepen, and I think that republicans need to get their heads round the fact that the crisis which arises solely from their failure to keep their promises is liable to get worse in the near future", Mr Trimble said.
The UUP leader conceded it was likely the document would propose that former paramilitary prisoners be entitled to sit on bodies governing the Police Service of Northern Ireland.
"I think on that it is perfectly obvious there will be people on the police board and district policing boards who are coming from the appointees drawn from the Assembly and the councils", he told BBC Radio Ulster.
"In view of the make-up of the councillors and the Assembly, that's likely to contain people who have paramilitary backgrounds. That's obvious.
"The question is what safeguards do you then have to ensure that such persons . . . do not have an improper influence on policing? That's a matter for the police command structure."
Sinn Fein's chief negotiator, Mr Martin McGuinness, said that his party would study the document carefully but he had no reason to expect any statement from the IRA either before or after its publication.
Mr McGuinness said that the package could not come too soon for Sinn Fein. The party would study it "to see how it matches up to the Good Friday agreement and whether it has the potential within to fully implement the Good Friday agreement".
The SDLP's Minister of Employment and Learning, Mr Sean Farren, urged all parties to seize the opportunity presented by the joint set of proposals. He claimed that the recent street violence was "feeding off the political uncertainty" and had the potential to develop further if there was no breakthrough.
"Deepening community divisions are being exploited by anti-agreement forces with the aim of undermining prospects for political progress", Mr Farren said.
"The Good Friday agreement promised a complete and unequivocal adherence to peaceful and democratic politics. What we are witnessing on the streets of Belfast and in attacks on homes and property across the North is the very opposite of that promise."
Mr David Ervine, of the Progressive Unionist Party, said many unionists feared the proposals would amount to little more than a "wish list for republicans".
The DUP's newly elected MP for Strangford, Mrs Iris Robinson, said she expected the document to contain further concessions to republicans which would come as a great insult to most unionists.
She said: "The talks at Weston Park have opened up another can of worms as far as unionists are concerned, for now we are told that further demands on policing, demilitarisation and inquests have been conceded by the pro-agreement parties."
Mrs Robinson said Mr Trimble's admission that he expected former prisoners to be allowed to sit on police boards would shock many people in the North, "in particular those members of the RUC who investigated, arrested and convicted many of those who will now sit on boards overlooking their jobs".