The Ulster Unionist Party and the DUP have responded negatively to British-Irish proposals unveiled yesterday to create an all-island economy.
The UUP said the British-Irish document sought to transform Northern Ireland "into a colony of the Republic", while DUP MP Gregory Campbell said his party would never accept proposals that were tantamount to an "all-Ireland embryonic idea".
The most cutting criticism came from the UUP, with leader Sir Reg Empey warning the proposals could "poison" North-South relations. He used the economic blueprint to criticise the DUP, claiming that its proposals went way beyond what was agreed in this area in the 1998 Belfast Agreement.
"This document seems to be intent on turning the Northern Ireland economy from being a region of the UK into a region on the island of Ireland," he said.
UUP deputy leader Danny Kennedy also said the proposals were "an attempt to transform Northern Ireland into an economic colony of the Irish Republic".
"This document looks like it was written by a Sinn Féin policy officer and passed under the nose of an Irish Department of Foreign Affairs civil servant," he added.
"In 1998 the UUP faced down many of these 'nationalist' proposals. Now, by tinkering around the edges of the [ Belfast] Agreement, the DUP have opened up a Pandora's box and allowed the nationalist genie out of the bottle again," he said.
"The UUP is all in favour of mutual economic co-operation and trade between the two states. However this document is a different proposition entirely . . . while some of the infrastructure proposals have merit, we would reject the proposal as a whole as it runs against the very ideal of a vibrant, confident Northern Ireland within the union," added Mr Kennedy.
The DUP's Mr Campbell said economic co-operation between the Republic and the North must be practically, not politically, motivated. "What we in the DUP will be saying to Dublin is that if your understanding of this arrangement is that this money is designed to build up an all-Ireland economy, we are not going there. But what we will do is work with you in developing the concept of two adjoining countries who want to build up the structures of both countries," he added.
"If co-operation between Northern Ireland and the Irish Republic is the same as co-operation between other states elsewhere in the world and there is clear delineation between our two countries, then we have no problem. We are not prepared to consider now or ever an all-Ireland embryonic idea," said Mr Campbell.
Sinn Féin economy spokesman Mitchel McLaughlin said his party had "consistently argued the only way to address the structural weakness in the six-county economy and particularly the imbalanced economic development affecting the Border region and north-west is through the development of an all-Ireland economic vision".
"This blueprint must be supported by a substantial financial commitment from both governments. Sinn Féin have argued that a £10 billion 10-year peace dividend to support the creation of 140,000 jobs and major investment in infrastructure is required," added Mr McLaughlin.
SDLP senior negotiator Seán Farren said the overriding objective of any joint governmental funding for the North must be to regenerate the economy, address disadvantage and promote reconciliation.
"With significant investment in our infrastructure and in our people and a step-change in levels of co-operation with the Republic, the SDLP believes that we can grow a prosperous economy and an inclusive society. We believe that this announcement is a crucial step along this road," added Dr Farren.
Northern Secretary Peter Hain said the proposals represented a new level of North-South economic co-operation.
He said it "sets out a compelling vision of a strong, competitive and socially inclusive island economy".
