Ian Paisley's Democratic Unionist Party today dismissed as "fantasy" any idea of it taking part in early negotiations with Sinn Fein over the resumption of power sharing even if the IRA disarms.
The republicans are widely expected to announce the completion of decommissioning within the next week or two.
But the DUP made it clear British Prime Minister Tony Blair was wrong if he thought that would signal a rush from the main voice of unionism to restore the power sharing administration at Stormont.
North Belfast MP Nigel Dodds said the British government had decided to do a deal with republicans of which his party was not part.
"They will find short shrift from us if they think they can act in this way and then just expect us to meekly acquiesce in their plans to get Sinn Fein into government," said Mr Dodds.
He accused the British government of caving in to the IRA on the issues surrounding the full verification and transparency of the decommissioning process.
At the same time it had dropped the requirement for the disbandment of the IRA as an organisation.
"In so doing they are deliberately making the process into something that will not build confidence in the community," he said.
Mr Dodds added: "It has rushed with obscene haste to deliver concessions to Sinn Fein and treated the elected voice of unionism with disdain."