The Ulster Unionist leader has said the Westminster election will "determine the future" of the North.
Mr Trimble told an audience of party members and businessmen that both republicans and hardline unionists wanted to make the agreement fail and urged unionists to come out and vote to preserve it.
Mr Trimble said the vast majority of people in the North wanted the agreement to work but warned that the DUP and Sinn Fein were "two sides of the same coin, they want to control Northern Ireland on their terms.
"The DUP, relying on bluster, have the delusion that they can go back to yesterday. Sinn Fein, relying on intimidation and lies, look for a tomorrow in which we are run jointly by London and Dublin".
If the agreement was to be preserved, Mr Trimble said its supporters had to "come out and be counted. They have to turn up at the polling booths next Thursday and vote for constructive politics".
In the past, voters from both communities had shunned politics and left a vacuum in which violence could flourish, but the UUP leader said there was no excuse for a low turnout now.
"Next Thursday will determine the future of Northern Ireland. You can be certain that the DUP will come out in force. You can be certain, too, that Sinn Fein will be out in force - and that some of its members will be voting early and often."
Some unionists might be tempted to stay away because they disliked a candidate, or aspects of the agreement, he said but added that "there is nothing admirable about refusing to cast a ballot".
The DUP leader, meanwhile, urged unionists to use their vote as a weapon to "sweep away" the leaders who had failed them since the signing of the Belfast Agreement.
The Rev Ian Paisley claimed there was a "crystal clear" division between his party and the Ulster Unionists over the agreement. Predicting significant DUP gains in both local and Westminster elections, he urged voters to punish Mr Trimble and his party at the ballot box.
"Unionists have a weapon, the weapon of the ballot box," he said. "I call upon them to use that weapon to sweep away a unionist leadership which has so singly failed our province in its greatest hour of testing.
"The unionists of Northern Ireland have the power in their hands to break out of the net of treachery which has been thrown over them by Trimble and Co."
Dr Paisley said his party had never before received the kind of enthusiastic reception it was getting on the doorsteps. He also criticised the decision to make two retiring Ulster Unionist MPs members of the House of Lords.
Mr Ken Maginnis and Mr John Taylor had "received their rewards for their treachery. Their shame is to be covered by the ermine of the House of Lords. But that shame will out".
The Sinn Fein president predicted his party would have 100 council members after Thursday's local elections.
Mr Gerry Adams said that with 153 candidates standing he believed his party would boost its council representation substantially. "The number 100 is a nice round figure which would actually mark a one-third increase of Sinn Fein councillors," he said.
"I think we will see an increase of at least 10 per cent in our vote - maybe as much as 15 per cent - but I'll be satisfied if the increase is 10 per cent," he said.
In West Tyrone, the SDLP candidate Ms Brid Rodgers, said she and her workers had been pelted with stones and eggs by Sinn Fein supporters as they canvassed.
Vowing to continue her campaign, Ms Rodgers said: "They can tear down my posters, they can attack me and my canvassers, but they can't stop the will of the people.".
Ms Rodgers said her party was "ahead throughout the North, clearly winning, clearly growing in strength".
The Sinn Fein candidate, Mr Pat Doherty, denied any party member was linked to the attack. "This assumption that every time something happens it is down to Sinn Fein is nonsense," he said. "Our workers are too busy to be involved with anything like throwing stones.".