THE SDLP yesterday argued that a new assembly would enable unionists to block any serious proposal for an agreed political settlement.
Mr Denis Haughey said an elected body would alter the political balance and shift the focus of the peace process in a way that would gravely damage the prospects of a successful outcome.
Mr Haughey, the SDLP's mid Ulster representative, accused the British government of forging a "shabby deal" with the unionists.
He also stated that Mr David Trimble had yesterday wrongly conveyed the impression that the SDLP had engaged with the Ulster Unionist Party in a "positive exploration" of the elected body proposal.
The two sides had participated in what the SDLP understood, were confidential discussions, during which SDLP representatives stated in detail the party's opposition to an elected body, he said.
Mr Haughey said if an elected body were created, unionists, would then demand that all proposals, and all measures, would be tested in the assembly and that only those measures supported by a unionist majority could be taken any further.
What he called "this assembly test" would replace the decommissioning precondition as the next roadblock to progress.
"Unionists have always sought to confine dialogue and negotiation within a Northern Ireland framework. Within that framework, they have a majority, and they always win," he added.
Mr Haughey said that setting a mandate for a new body would take months to negotiate as unionists quibbled over "every full stop and comma".
"The result of all this would be many months of delay, perhaps a year or more, and the outcome would be a fresh mandate for unionist intransigence. And, of course, within a year, and perhaps within months, a Westminster election will be upon us, throwing the whole process into further disarray."
Mr Haughey said that Mr John Major and the unionists were still "hung up" on the decommissioning precondition. "They have both made it clear that elections would not remove that precondition. Now, if that is their position, what is the point of an elected body?"
He said that instead of building", trust, Mr Majors proposal had: "deeply alienated the Irish side of the equation. Once again, as so, often in the past, the survival of a particular British administration takes precedence at Westminster over peace in Ireland."
