THE Ulster Democratic Party and the Progressive Unionist Party will return to the Stormont talks on Monday, to face a unionist challenge to their right to be there.
The UUP is planning to ask the Northern Secretary, Sir Patrick Mayhew, to examine the position of the loyalist groupings in the light of the bomb attempts on leading republicans in Belfast and Derby before Christmas.
The DUP leader, the Rev Ian Paisley, and the UK Unionist Party leader, Mr Robert McCartney, are expected to go even further by demanding the expulsion of the UDP and PUP.
The main unionist parties will submit that because of the actions carried out by the loyalist paramilitaries (though not formally admitted by them) the fringe parties must be in breach of the Mitchell principles on nonviolence which they signed when the talks began last June.
The outcome of the debate will very much depend on the view taken by the chairman, Senator George Mitchell, and the two governments.
This issue will probably distract the parties initially from the unfinished wrangle about decommissioning, about which they were deadlocked when they adjourned before Christmas.
Mr Mitchell and his colleagues had hinted that they might seek to test their authority as chairmen in order to push the parties towards a resolution of the decommissioning issue.
They said in a pre Christmas statement: "In the light of recent indications of some convergence on certain issues, we will explore whether there is a basis for exercising the authority conferred on us by the rules of procedure, in circumstances where there is no unanimity on an issue, to put forward a solution we believe will secure agreement on the handling of decommissioning.
Before this arises, however, the parties will have to deal with the position of the fringe loyalists. They will be acutely aware that as long as the Combined Loyalist Military Command refrains from formally renouncing its ceasefire, there are grounds for hoping that loyalist paramilitary violence can be contained.
A decision to expel the UDP and PUP, however, would reduce the incentive for the CLMC to slide back and would greatly increase the likelihood of a slide back into full scale sectarian conflict.