The two DUP ministers in the Northern Ireland Executive yesterday said they would resign if all the Ulster Unionist members did so following Mr David Trimble's expected resignation as First Minister. He is due to resign at the end of this week.
The DUP's East Londonderry MP, Mr Gregory Campbell, told the Assembly he would stand down as Regional Development Minister, and his colleague Mr Maurice Morrow would resign as Social Development Minister, if Mr Trimble's entire team followed his lead and pulled out of the Executive on Sunday.
He said: "My party colleague Maurice Morrow and I have tendered a letter of resignation effective on the resignation of all the Ulster Unionist ministers."
Mr Trimble has given a letter of resignation to the Assembly Speaker, Lord Alderdice, to take effect on Sunday unless there is satisfactory movement by the IRA on decommissioning.
Mr Campbell said his threat to resign was intended to "send the clearest possible signal that the current system does not command the support of the majority of unionists in Northern Ireland. We are committed to finding an accommodation which can also command the support of a majority of unionists in Northern Ireland.
"In pursuing this aim we will talk to anybody but we will not sit down and negotiate with those who are not committed to exclusively peaceful and democratic means.
"We shall not act in a way which would simply hand over government departments to those who support the Belfast Agreement, but we will act in the best interests of all the people of Northern Ireland."
He added: "Today we challenge the First Minister to see if he is serious about decommissioning."
But the DUP's move was dismissed by Mr Trimble, who claimed the resignation letters they had lodged would have no effect.
He told Mr Campbell: "Two things stand out. First of all, he [Mr Campbell] is incompetent. He hasn't read the [Northern Ireland] Act. The letter he had lodged has no effect because a letter of resignation, if he can read the Act, should be sent to me and the Deputy First Minister. Sending it to the Speaker has no effect at all.
"Second, he is a coward. He is a political coward. If he had any courage he would go now, and what is he going to do? He said that after I resign he might think about it. He is content to follow me and by saying that he is showing that he and his party regard me as being the leader of unionism."
The DUP's move was also condemned by the UUP Minister for Culture, Arts and Leisure, Mr Michael McGimpsey, who claimed the DUP had "no political strategy and no political integrity".
The SDLP Finance Minister, Mr Mark Durkan, accused the DUP of trying to pull off a "shadow stunt".
He continued: "Mr Speaker, it has been clear to many of us outside of unionism for some time that there are two groups on David Trimble's back. Those within his party are there because they are trying to bring him down.
"Those in the DUP are there because they are quite happy to piggy-back on David Trimble and the success and workings of the agreement."
Sinn Fein's national chairman, Mr Mitchel McLaughlin, said: "The message that you hear from broad nationalism and republicanism - and I direct this to all of those on the opposite side of the house - is if there are problems, and yes, there are problems, we can resolve them through dialogue, through negotiation through commitment to politics.
"If we measured the progress over the past number of years against our collective experience of political failure, then there is only one option.
"That is that we continue on this path, that we take our courage in our hands, that we exercise the mandate which we got to deliver peace, democracy through negotiations, through agreement, through mutual respect.
"We will solve the problem, the outstanding problems of militarisation in our society, of policing in our society, of criminal justice reviews, and the question of arms.
"We will resolve this by agreement and through applying ourselves in a diligent, sensible fashion. For people to set ultimatums, for people to expect unrealistically that we can resolve the problems of generations in a matter of months, is in fact to betray the expectations of those who voted for the Good Friday agreement."