The Royal Ulster Constabulary yesterday questioned seven IRA suspects over the murder of senior Ulster Defence Association member Bobby Dougan. If it is proved that the killers belong to the IRA then Sinn Fein's participation in the talks is thought to be untenable.
Mr Dougan was the second man to be killed by republican terrorists within 24 hours. Earlier, drug dealer Brendan Campbell was shot, it is thought, by gunmen from Direct Action Against Drugs, an IRA front organisation.
In a separate incident, Mark Fulton, a friend of the murdered former leader of the Loyalist Volunteer Force, Billy Wright, escaped a murder bid in Portadown which he blamed on the Progressive Unionist Party and its military wing the Ulster Volunteer Force - a claim denied by PUP spokesman David Ervine.
While investigations continued into the two murders, the security forces prepared for possible loyalist revenge attacks on Catholics, and the prospect of internecine warfare between Protestant paramilitaries.
Some of the senior political leaders at the talks privately said the IRA was split over the process and that Sinn Fein leader Gerry Adams appeared to have lost ground against those calling for a return to conflict.
Mo Mowlam, the Secretary of State for Northern Ireland, gave the clearest signal so far that Sinn Fein could be thrown out of the talks, if hard evidence emerges of a link between the killings and the IRA.
Deploring the murders, which were condemned on all sides, she told MPs that it had not been "reliably established" that the IRA was responsible. "If and when it is, the Government will not hesitate to act to determine whether the party concerned has demonstrably dishonoured its commitment to the Mitchell principles."
Ms Mowlam insisted the talks process could go on without Sinn Fein, with John Hume's Social Democratic and Labour Party representing the nationalist community. "We still sticking by the 'sufficient consensus' rule. The SDLP are there and we should go ahead," she said.
Tony Blair also signalled that if IRA involvement was proved, then that would be the end of Sinn Fein's involvement in the talks. "It is the case that the rules must be applied in respect of any organisation that's bound to engage in paramilitary activity, so you can't have set one of rules for one group of people and others for other."
The talks are now likely to be dominated by Unionist demands for Sinn Fein to be removed when they resume in Dublin on Monday. They will cite the expulsion last month of the Ulster Democratic Party, linked to the Ulster Defence Association and the Ulster Freedom Fighters, after the UFF admitted involvement in three murders of Catholics. One of the options being considered, according to Northern Ireland Office sources, is to suspend rather than expel Sinn Fein, with the party being allowed back after a suitable period as long as the IRA maintains a ceasefire.Reuse content