Mr David Trimble has hardened the Ulster Unionist Party's opposition to significant cross-Border bodies with executive powers ahead of next week's transfer of the talks process to Dublin.
At a Westminster press conference yesterday, Mr Trimble unveiled a unionist blueprint which would firmly cast North-South meetings under the umbrella of what Mr Trimble still calls the council of the British Isles.
In view of "the already massive co-operation between the United Kingdom and the Irish Republic", the UUP says the council would enable discussion, consultation and co-operation and deal with "the totality of relationships within these islands".
According to the eight-page UUP proposal, "all meetings between ministers/heads of committees of the Republic of Ireland and the Northern Ireland assembly will take place in meetings of the council" - which would be convened at summit level at least twice a year.
As part of its attempt to replace and effectively reverse the 1985 Anglo-Irish Agreement, the UUP document suggests that where meetings between the British and Irish governments are held to discuss matters not devolved to a new Northern Ireland assembly, representatives of the assembly from each of the main traditions "shall be invited to participate".
The UUP suggests that decisions taken in the council must be on the basis of unanimity and that such decisions in any event have "only recommendary" status, since they would require the subsequent ratification of the respective assembly or parliament.
In a further blow to government hopes of greater unionist flexibility, Mr Trimble says the assembly should exercise powers akin more to those envisaged for the Welsh assembly than for the Scottish parliament.
Far from anticipating the emergence of an executive committee of the assembly acting as a cabinet, the UUP suggests the assembly as a whole would comprise the executive, with administrative functions carried out by committees whose chair and composition would be allocated "on a proportional basis as in some local authorities".
Mr Trimble said the blueprint, covering all three strands, offered his party's best assessment of where agreement was likely to be found. As Mr Seamus Mallon, the SDLP deputy leader, dismissed the proposals, Irish Government sources were hoping that the paper represented "a negotiating position" to see Mr Trimble through next week's Dublin talks rather than a definitive view of the likely shape of a settlement.
London was also clinging to that benign interpretation, in full knowledge that the UUP position as stated would exclude any possible agreement involving Dublin and the SDLP, let alone Sinn Fein.
The nagging worry in both capitals and among senior SDLP members is that Mr Trimble's gambit yesterday runs counter to the perceived need that he begin preparing unionist opinion for the compromises and adjustments necessary if agreement is to be reached. Mr Trimble's political opponents, moreover, can be expected to use yesterday's publication to measure any concession he might make as the talks process hurtles toward the May deadline.
Mr Trimble's interpretation of the recently published Propositions for Heads of Agreement has already been rejected by the two governments, who made it clear on the day of publication that the proposed North-South council and the council of the isles would be separate and free-standing.
Contrary to Mr Trimble's view, the effective umbrella for any new dispensation will be the standing machinery of the London-Dublin intergovernmental relationship.
The UUP document says there would be an effective prohibition on the assembly acting contrary to the European Convention on Human Rights, which would empower any aggrieved citizen to seek redress in the courts.
Consequently, the paper argues, "a cumbersome structure of checks and balances would be unnecessary". Such a structure "would focus on the two tribal blocks at the expense of others and, more importantly, ensure administrative gridlock".
The UUP says withdrawal of the Irish territorial claim would require deletion from Article 2 of the definition of the "national territory". This could be replaced with a definition capable of including those in Northern Ireland "who regard themselves as part of that nation". A revised Article 3 "should repeat the limitation of the effect of Dail legislation to the 26 counties so as to exclude any possibility of an exercise of jurisdiction over Northern Ireland".
The Northern Ireland assembly, it says, must have political efficacy and be "boycott-proof" with no incentive provided for nationalists to make it fail.
This issue is likely to gain prominence during next week's talks, as the UUP challenges the Framework Document provision giving the two governments powers of intervention and asserting that North-South co-operation would continue in the event of a devolved government failing.