The British Prime Minister must act as a guarantor of the Belfast Agreement, Sinn Féin president Gerry Adams said today.
Mr Adams said there were no grounds for expelling his party from the power-sharing and added that the Dublin Government must continue its opposition to any suspension of the institutions.
It was time for Mr Blair to show to republicans and nationalists that he was prepared to act as guarantor for the Agreement, he said.
Ulster Unionist Party leader Mr David Trimble has urged Mr Blair to expel Sinn Féin from the Executive after allegations of IRA intelligence-gathering.
But Mr Adams said this was ridiculous.
The current crisis, he said, had merely been brought forward from what would have happened following a UUP deadline for the IRA to disband in January.
"There is no basis for such a motion and David Trimble knows that," Mr Adams said.
"David Trimble's party decided to do post January of next year what they are threatening to do next Tuesday."
Mr Adams said he would attend a rally in Dublin tomorrow night while at the same time Sinn Féin education minister Martin McGuinness would be at one in Belfast to gather the views of party supporters on the current crisis.
Earlier, Mr Blair today told Sinn Féin that he needed to know that its members were committed to "exclusively peaceful means" if the Northern Ireland peace process was to succeed.
He said he believed that the republican leadership was committed to a peaceful future but warned that they could not remain part of the democratic process while still pursuing a "path of violence".