The Rev Ian Paisley has said that the Ulster Unionists must overthrow Mr David Trimble as their leader before he "betrays" the people of Northern Ireland any further.
Speaking at Stormont yesterday, the DUP leader claimed Mr Trimble was considering a deal which granted four substantial concessions to Sinn Fein:
The party's two Westminster MPs, Mr Gerry Adams and Mr Martin McGuinness, would be given offices there;
There would be dual sitting rights for the North's Westminster MPs in the Dail;
All Provisional IRA prisoners, both convicted and on remand, would receive an immediate amnesty and;
The RUC and British army would be withdrawn from Border areas.
Dr Paisley said unionists had been offered nothing except the appointment of a Provisional IRA go-between to the international decommissioning body. He claimed there was "absolutely no prospect" of a handover of weapons before May 2000 as outlined in the Belfast Agreement.
It was up to UUP Assembly members who fought an election on a "no guns, no government" policy to "declare themselves", he said.
"They have got to dissociate themselves from their leader. They would have to ditch him as leader. These are matters that have not been taken to the electorate.
"He has no mandate to even discuss these matters. If he had put them in his manifesto, he wouldn't even be here."
Dr Paisley said external pressures had toppled two previous unionist leaders who had attempted to compromise, Mr Brian Faulkner and Capt Terence O'Neill.
"That is what is going to happen again. The pressures outside are mounting and mounting very quickly against Mr Trimble. Guns before government - that is what Mr Trimble has run with and that is what people are going to demand he gets.
"There cannot and must not be gangsters and terrorists in any government in any democratic part of the UK. David Trimble is going to adopt the same attitude as in the past. He is drawing a line in the sand but he's prepared to remove the line and jump over it."
A UUP negotiator, Mr Michael McGimpsey, cautioned against hope of an immediate breakthrough in the Mitchell review.
"We have said repeatedly that we would like this review to come to a successful conclusion as quickly as possible, but that may not be possible today.
"Important matters still need to be clarified and settled. We ask people to be patient. But it's crucial that we have something that actually works."
The Northern Secretary, Mr Peter Mandelson, said he hoped the talks would be successful. Speaking after attending a Remembrance Day service at Stormont, he said: "Politicians should hear the cry of people.
"What we have here is a great hope for the future, the hope of returning proper politics back to a position of normality and stability."
The Northern Secretary, Mr Mandelson, in an apparent reference to the IRA decommissioning, was caught on camera urging an Ulster unionist Party Assembly to call the bluff of the republican movement, adds Gerry Moriarty.
Mr Mandelson was filmed by BBC Northern Ireland urging UUP assembly man Sir john Gorman to take risks in the review process.
"Put these people to the test," he said. "call their bluff a bit, that's my view. They say they are going to deliver. Let's see if they are going to deliver."
Mr Mandelson made the remarks in the great hall of Parliament Buildings, Stormont following the remembrance day ceremony yesterday morning.
The Rev Williams McCrea, a senior DUP Assembly member, said that Mr Madelson made similar remarks to him and other politicians at Stormont yesterday.
A spokesman for Mr Mandelson would make no comment.