Relations between the Irish and British governments have come under renewed strain in a potentially serious dispute about the British government bill creating Northern Ireland's new police service.
The Government is known to share SDLP and Sinn Fein concerns about the bill's failure to carry through key proposals of the Patten Commission for the reform of the Royal Ulster Constabulary.
And with Mr Seamus Mallon, Northern Ireland's Deputy First Minister, believed set to table some 44 amendments to the bill, the Secretary of State, Mr Peter Mandelson, was last night facing the possibility of a rebellion by some Labour backbenchers at Westminster.
Amid rising nationalist and republican anger about the provisions of the Police Bill, which some observers believe could yet have serious implications for the peace process, and the IRA proposals for putting weapons beyond use, the former shadow Northern Ireland secretary, Mr Kevin McNamara, broke ranks with a demand that Mr Blair's government "return to the drawing board" with its legislation.
Mr McNamara tabled a "reasoned amendment" to Mr Mandelson's bill, declaring it "does not provide for full democratic accountability, cannot lead to the creation of a police service capable of attracting and sustaining support from the community as a whole, and fails to reflect the determination of the Patten Commission".
In an outspoken attack ahead of next Tuesday's second reading debate in the House of Commons, Mr McNamara spoke of "growing anger" at Westminster that the bill had failed to produce the imaginative blueprint for policing set down by Patten.
"The current bill fails on all counts," he said in a statement. "The government needs to return to the drawing board on their proposed legislation, and produce a bill that reflects the implementation of all the recommendations of the Patten report."
Independent analysts have agreed that the bill fails to follow Patten in key areas concerning:
the proposed Oversight Commissioner.
the proposed provisions on transparency and accountability, specifically in relation to the powers of the new Policing Board to initiate inquiries.
the proposed provisions on human rights and balance in the new police service.
Mr McNamara's amendment goes on to say that the bill does not fulfil the commitment in the Belfast Agreement "to provide a new beginning to policing in Northern Ireland" and "does not recognise full and equal legitimacy and worth of the identities, sense of allegiance and ethos of all sections of the community in Northern Ireland, and does not give adequate recognition to the role of human rights protection in informing the ethos of the new service".
Mr McNamara and other Labour MPs are also certain to join Mr Mallon in pressing Mr Mandelson on what assurances, if any, were given to Mr John Taylor ahead of last Saturday's meeting of the Ulster Unionist Council on the subject of the RUC name-change.
Mr Mallon has already said no one has been able to tell him what Mr Mandelson means when he refers to "the title deeds" of the new service.
Specifically, the SDLP deputy leader is expected to press Mr Mandelson to say whether he proposes to define "The Police Service of Northern Ireland (Incorporating the RUC)" in the long title of the Bill, or whether the proposed amendment to the legislation will merely be descriptive, defining the new title as "The Police Service of Northern Ireland" and noting separately that the new service incorporates the RUC.
Steven Alexander adds from Belfast: The North's First Minister has said he believes documents on the future of policing given by Mr Mandelson to Mr Taylor do not contain anything not already announced in the House of Commons.
Mr David Trimble said he could not comment on the contents of Mr Mandelson's letters to Mr Taylor. However, he did not think there were any surprises in Mr Mandelson's position on the name of the police service.