The deputy leader of the DUP, Mr Peter Robinson, urged Ulster Unionist Party members to "topple" their leader, Mr David Trimble.
Speaking at the DUP conference, he declared: "Better by far that you topple Trimble now rather than give him time to drag this province step by step to Dublin. He has left the solid ground of unionism - don't wait for him; he's not coming back," he told the conference. "No one man has done so much to undermine the Union, divide unionism, endanger the safety and lives of the unionist people and erode our defences." He described the Belfast Agreement as "a vile concoction of brainwashing and professional mind manipulation".
Mr Robinson reiterated his party's pledge not to sit in an executive cabinet with "Sinn Fein/IRA" even if this resulted in his party being excluded from ministerial positions. "I would rather languish on Opposition benches with my conscience intact than be a First Minister without principles," he added. He said there were thousands of disenchanted people who voted Yes to the Belfast Agreement who were now "straining for the opportunity to make good their lapse of judgment". "A generation of terrorist war has inflicted a most dreadful price upon our society, but terrible though that war has been the consequences of retreat and surrender are even more terrible.
"Some unionists may have departed the battlefield, but for Democratic Unionists there will be no retreat, no freewheeling and there will be no surrender."
The DUP Assembly member for North Belfast, Mr Nigel Dodds, told the conference the new Northern Ireland Assembly represented a "perverted and corrupt" form of devolution and could not be compared with the devolved governments to be granted to Scotland and Wales. He described the Assembly as one "where a majority isn't a majority, where nationalists have an absolute veto, where Provo terrorists are in government and where Dublin has a role and a say in our future".
The DUP Assembly representative for Lagan Valley, Mr Edwin Poots, said the Assembly was not a form of "open and accountable government" as there had been only five plenary or open sessions of the Assembly held in five months.
"The important decisions being taken are not being debated on the floor of the House. The First Minister and his Deputy are trying to create more power for themselves."