Draft EU treaty shows '˜contempt' for Union and for GFA: Swann

His frank assessment was echoed by his party’s MEP Jim Nicholson and TUV leader Jim Allister, who described it as an attempt to “subvert the integrity of the United Kingdom”.

The text released by the EU negotiator Michel Barnier – which has to be finalised by next month – was supposed to put into legal terms the Joint Report agreed by Theresa May and European Commission president Jean-Claude Juncker in December.

It proposes how the principle of “regulatory alignment” agreed in December would be implemented if the UK fails to find technological or diplomatic solutions to keeping the border open.

If such solutions are not found, the text proposes, “the territory of Northern Ireland, excluding the territorial waters of the UK ... shall be considered to be part of the customs territory of the Union”.

But UUP leader Robin Swann responded that the draft was “nothing short of a move by the EU to annex Northern Ireland”.

He added: “It is a complete non-starter for unionists. No British government could accept this. It demonstrates complete and utter contempt for Northern Ireland’s constitutional position and also for the Belfast Agreement.”

It is absolutely clear, he said, that Leo Varadkar, Michel Barnier and EU Parliament Brexit lead Guy Verhofstadt are seeking to “exploit Brexit in pursuit of Irish unity”.

He added: “Those who voted to stay in the EU, didn’t vote to leave the UK and those who voted to leave the EU didn’t vote to leave the UK either.”

Dublin and Brussels claim they want to defend the Belfast Agreement, he said, yet they “quite happily” seek to undermine one of the core principles which brought peace to Northern Ireland – the principle of consent.

His party colleague Mr Nicholson warned the proposals would have “devastating implications for the constitutional integrity” of the UK.

“The proposals ... show a tremendous level of ignorance of the Belfast Agreement, a disregard for the principle of consent and disrespect towards the constitution of the United Kingdom,” he said.

“It is a clear departure from the text agreed in December. These proposals are tantamount to annexing Northern Ireland economically and politically away from the rest of the United Kingdom.”

Keeping Northern Ireland in EU customs territory and the single market with the rest of the UK outside would mean “whole swathes” of Northern Ireland laws and regulations would be set in the European Council and Parliament where the UK will have no seats, he added.

Meanwhile, Mr Allister said the EU, by its founding treaties, is supposed to respect the constitutional integrity of every member state. By contrast, he said, the draft treaty “seeks to subvert the integrity of the United Kingdom by demanding that Northern Ireland is hived off under EU jurisdiction into its customs union”.

He added: “It is becoming increasingly clear that the EU has no interest in negotiating a fair deal. Belligerent demands such as articulated today need not just to be faced down, but met with a demonstrable willingness to pick up the cheque book and walk away.”