The North's Education Minister, Mr Martin McGuinness, has called on the British Prime Minister to act decisively against British "militarists" to move the peace process forward.
The Sinn Fein Minister said only Mr Blair could break the "military mindset".
"People are expecting Tony Blair, who has acted positively in the past in this process, to move decisively to face down the militarists within the British establishment who have plagued this process from the very beginning," he said, and added that he saw the Northern Secretary, Mr Peter Mandelson, as part of that "mindset".
British and Irish officials were locked in talks in Belfast yesterday to try to agree on last-minute proposals to lay the foundations for talks after Christmas.
Mr Mandelson said yesterday he had to strike a careful balance between calls for dismantling of security installations and society's need for protection. In a speech at St Malachy's College in Belfast he said the price of getting it wrong could be another atrocity.
"I would like nothing more than to be able to remove the security installations that blight some of Northern Ireland's countryside. They don't exist in the rest of these islands, and I don't want them to exist here.
"But . . . politics is about weighing up rival claims, and I have to balance very carefully the calls to dismantle the security installations against society's need for protection. This is not a false choice I have constructed: it is a very real one. The price of getting it wrong could be another Omagh," he added.
Mr Mandelson said the British government's police reforms were aimed at delivering a police service which would command the respect of everyone in society and draw membership from all sections.
While his attempts at implementing the reforms had been a "bruising" and "hurtful" experience for many, the overriding aim had to be a lasting peace as envisaged in the Belfast Agreement, he told pupils.
"As with all the other issues in the peace process, the central question is simple: do you hold out for perfection even if it means running the risk of bringing the rest of the agreement down? After all, if we had held out for perfection over decommissioning we still wouldn't be at the starting block."