Unionist parties are clamouring for the removal of the republicans after last week's Royal Ulster Constabulary declaration that the IRA was involved in the killings of a loyalist figure and a suspected drug dealer.
Sinn Fein leader Martin McGuinness warned yesterday that expelling his party from the talks could mean shutting the door permanently to its return to the negotiating table."We could conceivably have a situation where people out there, who are attempting to destroy the peace process and any hope of a negotiated settlement, could conspire to create circumstances which would make it impossible for Sinn Fein to get back to these talks.
"This is a very dangerous and very grim situation".
Mr McGuinness also accused the Government of double standards, saying that when in May last year RUC Chief Constable Ronnie Flanagan declared that a number of loyalist paramilitary groups had broken the ceasefire, no attempt was made to expel their political representatives from the talks.
The Unionist parties are demanding Sinn Fein's expulsion for the IRA's alleged involvement in the murders in Belfast of loyalist Bobby Dougan and drug-dealer Brendan Campbell.
Four men will appear in a Belfast court today charged with murdering Mr Dougan. Last week, police held up to seven men, with RUC sources describing some of the men held as IRA suspects.
The Northern Ireland Secretary, Mo Mowlam, said yesterday: "In peace talks, no one wants to negotiate with a gun at their heads.
"That is why the Northern Ireland talks process is only open to those committed to the principles of peace and democracy."
The Irish Prime Minister, Bertie Ahern, issued a clear warning that Sinn Fein's place was in jeopardy.
The rules governing the talks were set down, he said. "If the facts are such that the IRA are involved, then it is a very serious matter - and the process is fairly clear."
Seamus Mallon, deputy leader of the SDLP, said he would wait to hear the evidence from Ms Mowlam but insisted the integrity of the talks had to be protected.
A decision which was morally and democratically right had to be taken. "We are all going to have to walk a tightrope. We have got to do the proper thing, we have got to do the right thing.
"If that proper thing and right thing takes a certain amount of courage, then we will have to show the courage."
Sinn Fein says it should not be expelled from the talks because IRA involvement has not been proved.
Two different standards of proof have been mooted: the written rules of procedure lay down that parties may be ejected if they have "demonstrably dishonoured" the Mitchell principles of non violence. Ms Mowlam is said to have decided, when dealing with the case of loyalists, that proof should be "incontrovertible". Yesterday there was controversy over which of these principles should be applied.
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