The British government will today redefine its requirements of loyalist and republican ceasefires and unveil a raft of measures designed to curb street violence, restore public confidence and secure the Belfast Agreement.
It is understood London has rejected unionist demands for a new "exclusion mechanism", bypassing the need for a cross community vote in the Stormont Assembly to expel Sinn Féin or any other party from the power-sharing Executive.
At the same time the Northern Ireland Secretary, Dr John Reid, is expected to tell MPs existing legislation empowers him to recommend sanctions against any party in breach of its commitment to exclusively peaceful means, and that he would not hesitate to use it in the event of future breaches of paramilitary ceasefires.
The emphasis is likely to be firmly on the future as Dr Reid and the Prime Minister, Mr Tony Blair, spell out the range of paramilitary activities which they believe must end if the Belfast Agreement is to survive a continuing collapse in unionist confidence.
Mr Blair is expected first to spell out what he means by testing the paramilitaries' commitment to peace "more rigorously over time" in answer to a question by North Down MP Mrs Sylvia Hermon.
Immediately after Prime Minister's Questions, Dr Reid is scheduled to make a detailed Commons statement addressing both the short-term problems of street violence and the underlying problems in the political process caused by ambiguity or lack of public confidence in paramilitary intentions.
The indications last night were that Dr Reid's statement would not be "heavy on possible sanctions." At the same time, he was set to remind MPs that he could ask the Assembly to consider a motion proposing the exclusion of any party from office if a related paramilitary organisation was deemed in breach of its ceasefire.
When he first set today's deadline for British government action, Northern Ireland's First Minister and UUP leader, Mr David Trimble, was urging London to effectively bypass the Assembly and take unto itself the power to exclude. At a Westminster press conference, he insisted that the very act of London taking the power would produce a "sea change" in paramilitary attitudes.
However there were signs last night that Mr Trimble may now be persuaded that the threat to use existing legislation in some future circumstance points the way to eventual suspension of the institutions established under the agreement if ceasefires are again breached.
It seems the British government will also seek a compromise with him over suggestions for some form of commission to "audit" the state of the paramilitary ceasefires, without diminishing the ultimate decision-making responsibility of the Secretary of State acting on the advice of his security chiefs.
There is cautious confidence in Whitehall that Mr Trimble might be reasonably satisfied with the terms of today's statements. However he was maintaining the public pressure on Mr Blair last night, telling The Irish Times: "If we get a damp squib today then in all probability August will be bloody and September could see a political disaster."
The threat of a September showdown with his anti-agreement critics still loomed large as Mr Jeffrey Donaldson MP rejected any idea of the parties "drawing a line" under past ceasefire breaches.
"Anything that falls short of an effective exclusion mechanism is not worth the paper it's written on," he insisted. "Equally, the idea that we can draw a line under Colombia, Castlereagh and the violence on the streets of Belfast is a non starter. Republicans must be held to account for what they have done, never mind what they might do in the future."
Meanwhile, three men in their mid-20s were in hospital in Belfast last night following a shooting in Ardoyne.They were taken from a house by a number of armed men and each was shot once below the right knee.
Trimble urged to join other unionists in excluding Sinn Féin: page 6; Blair should highlight successes of peace process, says Durkan: page 12;