The Democratic Unionist Party was tonight accused by its main rival of adopting a "parasitical" approach to the Belfast Agreement.
As Northern Ireland's tense Assembly Election entered its final week, senior Ulster Unionist Sir Reg Empey challenged the Rev Ian Paisley's party to explain why it had not walked away from Stormont on a point of principle.
The East Belfast candidate said: "There are people who have been benefiting from the Agreement, taking all the benefits such as membership of the Assembly and all the salaries that go with it, without contributing anything to its creation. That in my mind is parasitical behaviour.
"The DUP portrays itself as having this lofty position of opposing everything in the Agreement but the reality is they are participating in its structures.
"Why have they not taken a principled stand of saying we oppose this Agreement, we oppose these institutions and will not participate in them?" he asked. "It's because the DUP effectively accept all the institutions and are going to work the system."
Sir Reg's attack came as unionist, nationalist and cross community parties prepared for a frantic final push to persuade voters to come out and support them on Wednesday.
With 108 Assembly seats up for grabs, the battle for supremacy in nationalism between the SDLP and Sinn Féin is as fierce as it is in unionism between the DUP and Ulster Unionists.