The Taoiseach, the British Prime Minister and the leaders of the main pro-Agreement parties meet in London today to consider the political stalemate threatened by the DUP's huge electoral gains.
Speaking after meeting Mr Blair yesterday DUP leader, the Rev Ian Paisley, again ruled out sitting in government with Sinn Fein.
"There will never be any conditions when we will sit in government with any body of people, loyalist or nationalist, who have an army, and that army is being used against democracy," he said.
He called it an "extremely useful meeting" at Downing Street stressing his desire to see democracy "completely and totally" restored to Northern Ireland.
In Downing Street this afternoon Mr Blair and Mr Ahern will come under strong Sinn Féin and SDLP pressure to push ahead with the implementation of the Belfast Agreement, and commitments made in the British Irish Joint Declaration of last April.
Sinn Féin's Mr Martin McGuinness said last night: "We will once again be raising with them the outstanding commitments which they have yet to implement, including measures on policing, demilitarisation, criminal justice, human rights and equality." He went on: "We will also make it clear to them that the continued suspension of the political institutions is both unacceptable and untenable."