Sinn Féin will meet Mr Tony Blair this afternoon after yesterday's planned talks were postponed due to bad weather at Heathrow Airport.
Mr Gerry Adams, the party president, approached today's meeting warning that unionists are "raising the bar" too high.
Mr Adams claimed yesterday that republicans and the two governments had devised plans to ease previous crises in the peace process. But he warned: "Maybe it can be done again. But even if we do that, the bar which the unionists have raised is very, very, very high indeed. I don't see any sense at this time of any section of unionism running into the \ elections prepared to engage on a pro-agreement axis."
He said he appreciated that the continued existence of paramilitaries "creates a problem for everyone". But he added that nationalists and republicans "will look at a dormant and quiet IRA and how it has become a target for tactical manoeuvring within unionism, and then look at the ongoing killing campaign by the loyalists which almost passes unmentioned".
He said there was no doubt the process was in crisis. Sinn Féin's chief negotiator, Mr Martin McGuinness, borrowing some of Mr Blair's language, said all sides needed to be involved in "acts of completion".
He said the Downing Street meeting would be used by his party "to ascertain whether or not the British government is going to fulfil its commitments". He said Sinn Féin would continue to pursue the peace process, and to "continue to use our good offices to see that all conflict comes to an end".
A Sinn Féin source, commenting on possible IRA moves between now and the end of February, said all such talk was academic unless republicans see the British government's plans to "deal with the gaps" in its implementation of the Belfast agreement. Mr Adams has agreed to see Mr David Trimble early next week. The Ulster Unionist Party leader called for such a meeting after he held talks with Mr Blair on Tuesday.
Mr Trimble has voiced doubts about holding elections to a suspended Assembly in May, but Sinn Féin has countered, insisting that they go ahead. Any postponement of elections would require an act of parliament.
The current unease among the parties has been heightened by the decision of the Mr David Ervine's Progressive Unionist Party to withdraw from the talks process. Mr Ervine has claimed that he would not tolerate pressure to back to any deal concocted among the two governments, Mr Adams and Mr Trimble.
He complained about being cold shouldered in the current process.
The SDLP leader, Mr Mark Durkan, also meets Mr Blair at Downing Street this afternoon.
Yesterday he rejected the notion that Fianna Fáil could organise in the North and contest elections. This idea was referred to by the Taoiseach in a Sunday newspaper interview 11 days ago. Mr Durkan said such an idea would "create a degree of distraction" and damage nationalist prospects of ministerial jobs allocated under the d'Hondt system, which in turn, is based on party strength in the Assembly.
He said the SDLP was born out of the Civil Rights Movement in the North and had nothing to apologise for. But he added: "While we are a party based in the North, we are a party of the island for the island, and that is demonstrated by the breadth of support we see across party lines in the South."