Members of the House of Lords were yesterday asked to back the emergency legislation paving the way for direct rule to be re-imposed on Northern Ireland.
Cabinet Office Minister Lord Falconer of Thoroton introduced the Second Reading of the Northern Ireland Bill, which has already cleared the Commons.
It is expected to become law tomorrow after further Lords debate today.
Lord Falconer told the House of Lords he had hoped it would not have been necessary to bring forward such a measure.
He said: "There has been no further substantial progress to report and it has therefore become necessary to put this legislation in place, so that if it remains necessary - because cross-community confidence is collapsing - we can operate a pause in the operation of Northern Ireland's devolved political institutions from the end of this week.
"There is no doubt cross-community consensus has been severely dented by the absence of credible progress on decommissioning, in the absence of an unequivocal commitment or a specific time frame in which it will occur."
He said the agreement placed consent at the heart of the Northern Ireland constitution, enabling serious North-South co-operation to proceed.
The British Government was accused in the House of Lords
The Conservative former Cabinet minister Lord Tebbit told peers: "The tragedy is that in these past two years the government has deliberately and remorselessly thrown away every high card in its negotiating pack."
He cited the release of prisoners, allowing Sinn Fein members in the Assembly, and the RUC "dismembered".
"So don't blame the IRA for doing what comes naturally to it, what in its own words it does best. Blame those who have let the IRA get away with it."
The crucial issue was the intentions of Sinn Fein.
He asked: "Are they intending to divorce themselves from their army and behave as though they were democratic politicians, or are they intending to sweat this one out, reckoning that on past form it is government that will blink first, and it is they that will profit once again by their association with a murderous terrorist army?"