The Sinn Fein president will ask the British Prime Minister to intervene over the failure of the political parties in the North to meet the deadline on setting up the new power-sharing executive and all-Ireland council.
Mr Gerry Adams said he would contact Mr Tony Blair to explain his frustration at the lack of progress and to ask him to urge the North's First Minister, Mr David Trimble, to move quickly to establish the bodies which should have been set up by today.
Mr Adams held a one-to-one meeting with Mr Trimble at Stormont yesterday. Ulster Unionist sources described the meeting as "frank and hard-nosed" and said it was the worst of the four the two men have had. Sinn Fein is angry at the First Minister's reluctance to set up the institutions, while Mr Trimble is insisting the IRA must decommission first.
After the hour-long meeting Mr Adams said: "I told Mr Trimble that he and the Ulster Unionists are on a go-slow.
"I also told him he was in breach of the Good Friday agreement and his pledge of office. I was not impressed with his defence for failing to implement the agreement. There is a responsibility on all parties to the agreement to face up to unionist intransigence."
Mr Adams said he would contact Mr Blair as a matter of urgency. "I feel I have a responsibility to spell out very clearly to the British Prime Minister that he signed up to this agreement as well and that the Ulster Unionist Party are preventing the implementation of parts of the agreement he signed up to."
However, the First Minister blamed Sinn Fein and the Provisional IRA for the impasse. "It is the failure of the republican movement to honour the agreement and the commitment they made to us that is causing the problem. There are no other serious problems," he said.
"There is no sign of Mr Adams being prepared to seriously engage and to fulfil his obligations under the agreement."
Mr Trimble accused Sinn Fein of using yesterday's meeting as a publicity stunt. He also indicated that the Taoiseach, Mr Ahern, may visit Stormont on Monday where bilateral talks on the new institutions are due to take place. He was looking forward to Mr Ahern's contribution on the North-South bodies.
Meanwhile, Sinn Fein said it would hold a series of protests across the North today to "mark the failure of David Trimble to implement the Good Friday agreement". Republicans will gather in Derry, south Armagh, and Cos Fermanagh and Tyrone. They will also hold a picket at noon outside UUP headquarters in Glengall Street, Belfast.