The Conservative Party has served notice on the British government that it is seeking direct legislative linkage between prisoner releases and the decommissioning of paramilitary weapons.
Mr Andrew Mackay, the shadow Northern Ireland secretary, signalled his move during last night's second reading debate on the Northern Ireland (Sentences) Bill which saw Mr David Trimble join forces with the DUP, the UKUP and dissident Ulster Unionist Party MPs to vote against the government.
The DUP leader, the Rev Ian Paisley, questioned the Tory commitment to push the issue to a vote, and predicted that the Bill would "sail through" its parliamentary stages. But Mr Mackay assured him he would be tabling amendments today. If they were rejected by the government, and ministers did not produce acceptable alternatives, Mr Mackay said he would force a vote and would expect Dr Paisley's support in the division lobbies during next Monday's committee stages.
While not opposing the Bill's second reading, the Conservatives have reserved the right to oppose the measure - providing for the accelerated release of some 400 prisoners in Northern Ireland - at a third reading.
That raised the prospects of the first substantial piece of legislation implementing the Belfast Agreement being opposed on the floor of the Commons by a combination of Conservatives and anti-agreement unionists. The divisions within the UUP were again laid bare when Mr Jeffrey Donaldson, the Lagan Valley MP, said he, too, would table amendments requiring "actual and ongoing decommissioning" before paramilitaries could qualify for accelerated releases.
Although seated alongside Mr Donaldson earlier, Mr Trimble was not in the chamber for Mr Donaldson's speech, leaving only the anti-agreement MPs, Mr William Ross and the Rev Martin Smyth, in support of their designated parliamentary spokesman. Earlier in the debate, Mr Trimble said it was "essential to ensure that the tests and conditions are firm, watertight and adhered to in practice". He said the concept of early release of prisoners had caused his party considerable difficulty. "This is an interference with the normal judicial process for political reasons. It is therefore, in principle, undesirable."
Mr Trimble said it was a concept people would not find acceptable unless they knew there was going to be a genuine end of violence and a genuine peace. Mr Trimble said it was no accident that the programme for prisoner releases was scheduled to take place over a two-year period, the precise period by which decommissioning had to be completed.
Mr Seamus Mallon, the deputy leader of the SDLP, said he understood that the proposed early releases rankled, and he stressed that this was "not just a unionist sensitivity." In a powerful intervention, Mr Mallon said the proposal to release prisoners early was "an act of generosity and of vision" by the peoples of these islands, their governments and their representatives. Mr Mallon told MPs: "This Bill places a debt of honour on the shoulders of all paramilitary organisations and parties associated with them . . . where they owe it to the people who have mandated in the referendum that there can be no tricks, no strokes, we are playing for the future and that debt of honour will have to be paid."
However, Mr Mallon also warned that there could be no question of imposing preconditions now that had been considered during the negotiation process and rejected. Opening the debate, the Northern Ireland Secretary, Dr Mo Mowlam, insisted that membership of the IRA and the UDA, for example, would continue to be a criminal offence.
Dr Mowlam said: "A prisoner must not be a supporter of a terrorist organisation of the kind specified in this Bill - which means organisations that have not established or are not maintaining a complete and unequivocal ceasefire." However, she went on: "This legislation will not remove the ban on organisations that are proscribed under our anti-terrorist laws. The IRA or UDA, for example, will continue to be proscribed and membership of such organisations will continue to be a criminal offence."
Dr Mowlam caused some confusion when she suggested that republican prisoners transferred from Britain to the Republic prior to the Belfast Agreement would be required to serve their full sentences.
Mr Mackay said that was not the understanding of the Conservative front bench, and Mr Kevin McNamara suggested Dr Mowlam may have inadvertently misled the House because the agreement - reached after the transfers from Britain - committed both governments to measures on prisoner releases. The Bill received a second reading vote by 343 to 10.