The DUP is poised to replace the Ulster Unionists as the North's largest unionist party, said Mr Peter Robinson. It will then be able to force a renegotiation of the Belfast Agreement, he told the party's annual conference in Newcastle, Co Down.
Mr Robinson said he was looking forward to the next election and had a message for Sinn FΘin and the SDLP: "Your days of dealing with pushover unionism is over. The DUP's day has come."
He also stressed the need for unity among anti-agreement unionists. If Mr Trimble's internal critics failed to stop his "betrayal" at next Saturday's Ulster Unionist Council meeting, they should resign and join the DUP, he said.
Around 450 delegates attended the DUP conference on Saturday which senior party figures described as "the largest and most successful ever". Mr Robinson said it was in stark contrast to the UUP conference the previous week.
"Their numbers had thinned. Delegates were in sombre mood. Their grey faces, furrowed brows and slumped shoulders told the story. The whiff of embalming fluid hung in the air. The dirge-like drone from the platform announced the presence of the chief mortician.
"There he was, the dejected leader of the depleted ranks of a defeated party. The empty seats cried out more eloquently than any speech delivered. David Trimble you are history."
Mr Trimble was flouting the Trades Description Act by calling himself a unionist. "What sort of unionist would agree to the destruction of the RUC? What sort of unionist would agree to the release of unrepentant murderers from jail? What sort of unionist would agree to unaccountable all-Ireland bodies with executive powers?
"What sort of unionist would agree to place the representatives of armed terrorism in government? What sort of unionist would be suckered into accepting the IRA's phoney token scam in relation to decommissioning? If David Trimble is a unionist, then Bin Laden is an American patriot."
While not changing its principles or policies, the DUP must become "a welcome home" where anti-agreement unionists in other parties could feel "at ease". In an appeal to anti-agreement UUP members, Mr Robinson said: "You find yourselves isolated in a party in which you have grown up and to which you have been devoted.
"You are fighting for a party which has yielded up every principle you hold dear. I urge you to flee - like Lot - and not look back."
North Belfast MP, Mr Nigel Dodds, said DUP success was evident. "This is our best conference yet". He was confident of further electoral gains. Mr Ian Paisley jnr said the DUP gathering reflected the party's strength. "Young people, old people, people from the length and breadth of Ulster, everybody is here. This is a proud and historic moment for us. Feet are still coming through the gates and votes are still coming into the ballot box for this party."
Rev Willie McCrea said Mr Trimble's days were numbered. "You may be applauded by the world for your treachery but the people of this wee province will finally bring you, and those who supported you, down. Make no mistake, Davy boy, you will hit the ground like a lead balloon and all Gerry and Marty's horses and all their Provo men will not be able to put Humpty Davy together again."