DUP leader the Rev Ian Paisley will today stipulate IRA disbandment as his price for sharing power with Sinn Féin in any future inclusive Northern Ireland Executive.
His uncompromising message will come in his address to his party's 35th annual conference, just days before the British and Irish governments resume talks with the political parties about the restoration of the North's devolved institutions.
The DUP leader is expected to say: "There will be no inclusive Executive with Sinn Féin as long as the IRA is in business and engaged in criminality.
"The day for the inclusive Executive on such a basis is over for ever. It is buried in a Sadducee's grave from which there is no resurrection.
"That part of the [Belfast] agreement stinks in the grave, dug with spade of truth."
Senior DUP sources last night confirmed this meant IRA "disbandment" as the party's price for sitting in Executive government with Sinn Féin.
When pressed that the IRA could cease to be "in business" without formally disbanding, the sources replied: "That would not be credible."
It is understood British prime minister Tony Blair intends to make a high-profile speech in Northern Ireland in the coming weeks pressing his timetable for agreement on the resumption of power-sharing government ahead of fresh Assembly elections scheduled for May next year.
However, in his speech today Dr Paisley is also set to challenge Mr Blair and President Bush to apply the same "anti-terrorist" standard in Northern Ireland as elsewhere in the world.
The Irish Times understands he will say: "All around the world today, the United States and the United Kingdom are busy spreading the message of democratic values. I support them in their endeavours; indeed I welcome it.
"But I say to Mr Blair and Mr Bush that Northern Ireland will not settle for second best. We will not accept terrorists in our government. Those engaged in terror and organised crime are terrorists, and must be treated accordingly."
In a passage certain to delight his party faithful, Dr Paisley will go on: "I say, as we have joined you in your battle, if you are honest you must join us in our battle. You cannot be anti-terrorist in the whole world with the exception of Northern Ireland."
The Democratic Unionists meet in Belfast today for the first time since last year's Westminster election in which they won nine seats, eclipsing the UUP and deposing David Trimble.
Deputy leader Peter Robinson, who is also director of elections, is expected to trumpet the DUP's position as lead unionist party.
His address this morning may also indicate how the increased mandate is to be used as the push by the two governments gears up this month.
The DUP conference is a showcase event, rather than a primary policy-forming body. Just five motions are scheduled for debate, all of them highlighting key unionist concerns about the current political situation.
East Derry MP Gregory Campbell and North Belfast MP Nigel Dodds will demand what the agenda terms "fairness and equality for unionists".
Conference will be asked to back "a detailed long-term strategic plan to tackle deprivation in unionist areas" and which will target educational under-achievement in many urban Protestant areas.