The final weekend of campaign for Wednesday's Stormont elections has been marked by a row over alternative ways to govern Northern Ireland.

The anti-Good Friday Agreement Democratic Unionist Party has proposed that power should be given to the Ulster assembly or a "voluntary coalition" of parties, rather than be shared in an executive.

But nationalist SDLP leader Mark Durkan accused the hardline unionists of promising a return to "majority rule".

With the battle focusing as much on support for the landmark 1998 agreement as for the individual parties, the DUP are charged with making false promises that could not be delivered.

The government has insisted there will be no re-negotiation of the Good Friday deal whatever the outcome of Wednesday's poll.

The DUP is threatening to overtake David Trimble's Ulster Unionist Party as the single biggest bloc at Stormont.

Ian Paisley's party set out three alternative models to the power sharing executive which operated in Ulster before direct rule was re-imposed by Westminster last year.

But nationalists have claimed the DUP promise would be a return to the days of unionist control through the combined majority of protestant votes in either the assembly or among the electorate.

Durkan said on Friday the DUP's document was "half baked".

"They say they want a voluntary coalition which would exclude other parties. That is out," he added.

"What they really want is majority rule. That is out.

And he attacked other parties for fuelling DUP expectations that the agreement could be renegotiated.

"Outrageously, the Alliance Party now favours a voluntary coalition," he said.

"And Sinn Fein, by stressing that there are going to be negotiations after the elections, has only added fuel to the DUP's fire.

"Let me be clear. As far as the SDLP is concerned, the Good Friday Agreement is not up for grabs."

But DUP MP Gregory Campbell said voters could force a change in the devolution deal.

"Our proposals will be designed to create lasting devolution and be capable of being supported by unionists and nationalists alike," he claimed.

"Up until this election we had the artificial glass ceiling which said it is the agreement, the whole agreement and nothing but the agreement.

"With the publication of this we are going through that glass ceiling."