William Hague's office last night issued a statement reaffirming the Shadow Cabinet's support for the bi-partisan approach to Northern Ireland but expressing its "disappointment and concern" that the Government was refusing to accept Tory changes to the legislation.
Ministers fear the Tory opposition to the release of prisoners as part of the Good Friday peace deal could unravel the package, and there is threat that the Tory peers could wreck the legislation in the Lords.
The Tories are threatening to vote against the Northern Ireland (Sentences) Bill because they claim it fails to require decommissioning of terrorist weapons to begin before prisoners can be released. Andrew MacKay, the Tory spokesman on Northern Ireland, said last night: "We intend to vote against the third reading of the Bill because it is fatally flawed unless there are substantial amendments."
Mr MacKay denied the Tories were threatening to break the bipartisan approach, but Downing Street and the Prime Minister reinforced the message that Labour in opposition had maintained the bipartisan approach, in spite of criticism, and they expected the Tories to do the same.
In an attempt to avert a vote against the legislation, Mo Mowlam, Secretary of State for Northern Ireland, was involved in 11th-hour negotiations with David Trimble, the Ulster Unionist leader, to amend the Bill before its third reading tonight. It appeared that Mr Trimble may have been satisfied by the deal.
Two amendments have been agreed by Ms Mowlam placing an obligation on the Secretary of State to follow specific criteria over the release of prisoners, and a third will appear on the Commons order paper today requiring the Secretary of State to "implement" the agreement, which links decommissioning of weapons with the release of prisoners.
Mr Blair told MPs: "Those parts of the package which relate to decommissioning have to be obeyed."
He told Mr MacKay that the agreement on which the people of Northern Ireland voted in the referendum could not be rewritten in any way, but he added: "We will look very, very carefully at any amendments that are tabled." Rebuking the Opposition, for its lack of support, he reminded Mr MacKay: "We supported the previous government through thick and thin on this."
As Northern Ireland's marching season approaches, Adam Ingram, Minister of State at the Northern Ireland Office, told the Commons during Questions that there would be "no excuse whatsoever" for violence at the marches.
Part of a North Belfast Orange Order Parade has been re-routed and Mr Ingram praised the Order for its agreement.
"I would like to welcome the acceptance by the Loyal Orders of the commission's determination in the re-routing of the Tour of the North parade scheduled for this Friday," he said. "All of us will recognise the full impact of any outbreak of violence, as we've witnessed in previous years, in the marching season.
"It not only damages the economic health and future well-being of Northern Ireland, it damaged the psychological and physical health and well-being of all of the people in Northern Ireland as well."Reuse content