The Conservatives have opened a fresh assault on the Blair government's controversial "OTR" (on-the-runs) legislation for dealing with paramilitary fugitives - warning that key elements of it could be in breach of the European Convention on Human Rights.
The warning, from Northern Ireland spokesman David Lidington, coincided with a statement by the London-based British Irish Rights Watch expressing its concern that the Northern Ireland Offences Bill - due to receive its second reading in the Commons tomorrow - would allow agents of the state guilty of collusion with loyalist terrorists to avoid being held to account for their crimes.
Mr Lidington last night raised the possibility that it was precisely this aspect of the new bill that might eventually face a legal challenge in the European Court.
The government has been hoping the inclusion of the security forces in the scope of the new legislation might alleviate unionist opposition to a scheme they and a cross-party coalition of opponents regard as "an effective amnesty" for OTRs and others, loyalist and republican, in respect of crimes committed prior to the Belfast Agreement.
Mr Lidington has been critical of the plan to extend the provisions of the bill to cover members of the security forces in respect of crimes committed in relation to terrorism in Northern Ireland, whether or not committed in pursuit of terrorist goals. He and Conservative deputy leader Michael Ancram have argued that the proposed "equivalence" between terrorist organisations and the legitimate forces of the state marks a reversal of British policy as maintained over the past 35 years.
Opening his new line of attack, however, Mr Lidington said that if the legal opinions he was receiving proved correct then "the assurances [Secretary of State] Peter Hain is trying to give unionists would be completely meaningless".
The possibility raised by Mr Lidington is that republican and loyalist paramilitaries would benefit from the passage of the legislation, with a successful legal challenge only subsequently establishing that its provisions could not be extended to members of the security forces. In his introduction to the bill Mr Hain insists that its provisions are human-rights compatible.
The SDLP's Alex Atwood welcomed yesterday's statement by British Irish Rights Watch, saying they had "hit the nail on the head" and warning: "The British government are getting this badly wrong if they believe there can be reconciliation if the truth of state and paramilitary killings is suppressed."
Meanwhile, The Irish Times has learned that the SDLP has asked for a meeting with Taoiseach Bertie Ahern to discuss its fears about ongoing discussions between the British and community-based groups about restorative justice schemes in the North.