THE SDLP has strongly denied unionist claims that the party's decision to withdraw its elected members from the Forum represents an attempt to end the entire peace process.
However, there are indications that the SDLP delegation at the multi party peace talks will vigorously challenge the commitment and adherence of the two main unionist parties, the UUP and DUP, to the Mitchell principles of democracy and non violence.
By signing up to those principles, the UUP leader, Mr David Trimble, and the DUP leader, Dr Ian Paisley, affirmed their "total and absolute commitment" to democratic and exclusively peaceful means of resolving political issues.
The SDLP will argue that the encouragement lent by the two unionist leaders to the Drumcree Orangemen and the associated loyalist blockade throughout the North represented a breach of that first and most fundamental of the Mitchell principles.
The SDLP deputy leader, Mr Seamus Mallon, said on Saturday that the confrontation created at Drumcree represented the use of a threat of force to influence political decisions.
However, while Mr Mallon might seem to have a good prima facie case that the unionist leaderships were in breach of the Mitchell principles, it is not clear from where an objective and definitive adjudication on this might be forthcoming.
Senator George Mitchell, as coauthor of the principles, is the obvious man to make a judgment. However, for the sake of keeping the talks process intact, he is unlikely to do so.
On the other hand, the issue raises the question: do the Mitchell principles mean anything if there is no authority or authoritative figure willing to interpret them and to adjudicate on possible breaches by the signatories?
Mr Mitchell may, of course, choose to conclude that the evidence against the unionist leaderships is purely circumstantial and insufficient to convict them formally of a breach. This would appal every nationalist in the North and would also contradict the plainly expressed conclusions of the Taoiseach, Mr Bruton, and his Ministers.
The other argument, of course, is that Mr Mitchell can do nothing, since the parties to the peace talks have simply signed up to the principles without giving him the authority to ensure that they are implemented.
The SDLP's withdrawal from the Forum is not unexpected, as the party had consistently criticised the concept of such a body - arguing that the total focus should be on the negotiations to find a comprehensive political settlement.
The SDLP had given a qualified commitment to participate in the Forum - in those aspects of its deliberations which might assist the stated purpose of promoting dialogue and understanding, but not where it began to impinge on the conduct or course of the peace negotiations.
But the unionist parties have signalled their determination to make an issue of the SDLP's abandonment of the Forum. The UUP deputy leader, Mr John Taylor criticised the decision as an attack on the whole peace process. He said the Forum and the peace talks went together and had an uncertain future if the SDLP pulled out of one.
The Taoiseach, Mr Bruton, yesterday endorsed the SDLP decision. He said in a statement: "I know from conversations with SDLP members in the past 24 hours that the frustrations that led to the party's decision to withdraw from the Forum are enormous.
"It is in the all party talks rather than the Forum that the real hope of a resolution of the present difficulties lies. Efforts must be redoubled to make the all party talks a success.
However, there is no doubt that the difficulties facing the peace talks have been multiplied enormously by recent events and Mr Mitchell and his fellow chairmen, Mr Harri Holkeri and Gen John de Chastelain, now face a much tougher task - along with the two governments - to hold them together.
It appears that if the peace talks at Stormont are to have any impact on the political situation in the medium term, it will not be enough merely to keep them "ticking over" - laboriously teasing out procedural details.
Mr Mallon has indicated that the SDLP wishes to clarify anew with Mr Mitchell the basis for any negotiations in the new circumstances. It will require "a clear understanding as to how we are going to proceed".
Even Mr Mitchell's considerable diplomatic skills may not be enough to enable him to provide such clarity and definition. Without the unstinting co operation and goodwill of the unionist parties - qualities which have been singularly absent in recent times - his hands would appear to be shackled.
THE following is the text of the SDLP statement on Saturday:
"The SDLP met today in Dungannon to review the grave situation created by the Orange Order's defiance, supported by unionist parties, of the rule of law over the past week and the authorities' capitulation to violent threat.
"The SDLP deplores the continuing street violence and reiterates the call for restraint and for all to use their influence to prevent any further disorder, destruction, injury and loss of life. Violence can neither resolve the problems we face nor redress the issues which have caused intense anger and frustration. Meaningful negotiations remain the only basis upon which to develop the peace process leading to equality and agreement. The SDLP has been in close contact with the Irish Government and is seeking urgent formal meetings with both governments.
"The issues raised by this week's events are fundamental and have seriously damaged the trust and confidence essential to the political process. Both governments recognised in their February 28th communique that confidence building would also require that the parties have reassurance that a meaningful and inclusive process of negotiations is genuinely being offered to address the legitimate concerns of their traditions...
"The SDLP will also ask for a meeting with Senator George Mitchell and his colleagues to stress the urgency of addressing the critical issues as they impinge upon the negotiations.
"The SDLP has concluded that there is no longer any basis for the party's continued participation in the Northern Ireland Forum. The party's members of the Forum are, therefore, tendering their resignations from that body."