The SDLP has said it will not accept "any variation of majority rule", and a peace settlement in the North would have to guarantee that "no decision would ever be taken again on substantive matters without the consent of the nationalist community".
In a strongly worded address to the media at Stormont yesterday, the deputy leader of the SDLP, Mr Seamus Mallon, said this message would be "hammered home" to the British Prime Minister and other parties at the talks. His comments came after major differences emerged between the SDLP and the Ulster Unionist Party on how an assembly should operate.
While the UUP is advocating a committee system, the SDLP wants one based on collective responsibility with a cabinet of ministers making decisions.
The SDLP would never accept a "Belfast City Council-style administration", Mr Mallon said. Until recently, unionists controlled the council because they had majorities on all the important committees. The Alliance Party, which now holds the balance of power, is also opposed to the assembly system proposed by the UUP.
Mr Mallon said one of the founding principles of the SDLP was that the representatives of the nationalist community "must be present, must share responsibility and must have access at every single level to the whole process of political power".
The assembly would have to be a full executive, decision-making body based on the involvement of the two communities. There would have to the safeguard of sufficient consensus, which could also be termed parallel consensus between the two communities.
The SDLP would also insist that the assembly could exercise executive and legislative power and could play "a full and meaningful role in the North-South council of ministers where that executive power would also be recognised".
The leader of the Alliance Party, Lord Alderdice, also criticised the UUP for its insistence on a committee system, which he said would be unreasonable and unworkable. It "would mean unionists could vote down on every committee and in the assembly as a whole, things they didn't like". If votes were taken on a majority basis in committees, the chairman would be a prisoner of a committee dominated by unionists.
The UUP leader, Mr David Trimble, said a committee system operating on the principle of proportionality would be more inclusive than what he termed "a Westminster model operating on collective responsibility, a cabinet system". He said it would not be possible to have a system incorporating both collective responsibility and proportionality.
Earlier the Minister for Foreign Affairs defended the Government's approach to changing Articles 2 and 3 of the Constitution. Mr Andrews said the Government had to make a judgment on the kind of constitutional change which would be acceptable to the Irish people. Ultimately the people would decide if the peace package was acceptable.
He had difficulty understanding why people had a problem with enshrining the consent principle in the proposed amendments, guaranteeing citizenship rights to everybody born on the island and expressing the legitimate aspiration to unity based on the principle of consent.
Mr Andrews said the Government was concerned with the need for balanced constitutional change, North as well as South, and meaningful North-South bodies which would have to be "deep and meaningful" and would have to have very strong, meaningful implementation powers. They must not resile from North-South arrangements as set down in the Joint Framework Document. Mr Andrews said the Government would have difficulty changing Articles 2 and 3 without such bodies.
Earlier, after a meeting between a Government delegation and the Ulster Unionist Party, Mr Trimble said drafts of proposed amendments of the Constitution which appeared in recent newspaper re ports were unacceptable. "It preserves the whole island of Ireland as the territory. It is drafted to regard all the people on the island as members of the nation and it fails to recognise the existence of Northern Ireland," he said.
It also overstated the aspiration to unity in terms which could preserve the constitutional imperative.