Weekend sees no let-up of pressure on Donaldson as TUV warns against agreeing a Protocol deal 'at the toxic price' of the Union's security

The TUV leader issued a shot across the bows of “fellow unionists, tempted to stretch themselves to secure a deal,” stressing that, since the Supreme Court last week found that the Protocol has put parts of the Acts of Union 1800 into suspension, “the critical test of any Sunak deal with the EU will be constitutional, not economic”.

Ex-Prime Minister Boris Johnson also entered the fray on Sunday, briefing the media that it would be “a great mistake” to kill off the Northern Ireland Protocol Bill.

The bill was the government’s answer to EU intransigence over the Protocol, and would give UK government ministers legal powers to basically suspend it – though the bill’s progress has been paused while negotiations with Brussels go on.

Influential loyalist activist Jamie Bryson said today that any deal with the EU must fully restore the Acts of Union and stop the European Court of Justice (ECJ) from ruling on Northern Irish matters.

"No self-respecting unionist should even consider trying to finesse or compromise on those fundamental issues,” he said.

All this comes after the chairman of the Loyalist Communities Council – which includes figures from the paramilitary underworld – warned in Saturday’s News Letter that if the DUP buckles, then the current leaders of the UDA and UVF will come under pressure “big time” from furious rank-and-file members who could oust them and stoke disorder.

Mr Sunak was in Belfast on Friday in an apparent bid to prime the Province’s five main parties for a pending deal in the days or weeks ahead – though he seemingly divulged no details about what shape this is taking.

There has been speculation that its main component is a compromise with the EU over cargo checks, by creating a “green lane” which would let lorries bearing cargo for the NI market proceed off the ship check-free, whilst other vehicles submit to inspections.

Mr Allister’s political stock has risen in recent times, with opinion polling indicating greater support for the TUV – likely to be the result of his vocal opposition to the Protocol, amid disenchantment in some loyalist circles with how the DUP was handling the issue.

In a statement today, he said: “When all is said and done the critical test of any Sunak deal with the EU will be constitutional, not economic.

“It is the imposition and supremacy of EU law and subjection to the EU Customs Code which have Article 6 of the Acts of Union in suspension.

"So long as Northern Ireland is, in customs and single market terms, EU territory, where their laws apply, then, whatever the spin, our constitutional position is fundamentally altered.

“I caution fellow unionists, tempted to stretch themselves to secure a deal, not to fall for the carrot of access for NI to the EU single market, because that comes at a toxic price, namely, supplicant acceptance of EU law and its ECJ.

“If NI is to be outside the EU then we must of constitutional necessity be outside its single market and customs regime.

"Of course, to trade into the EU market, or any other market, (as is the case for GB) our goods must meet their standards, but none of that requires membership of their single market, nor a dual regulatory regime.

“With the UK outside the EU economic and legal orbit then that is where NI too must be.

"Our constitutional and trading position is not the stuff of venn diagrams, where we straddle both legal orders, but must be as proscribed by the Acts of Union – no ifs, no buts.”

The DUP’s seven tests, set out in 2021, are:

1 – New arrangements “must fulfil the guarantee of the Sixth Article of the Act of Union 1800”. This essentially requires that everyone in the United Kingdom is entitled to the same privileges, and be on the same footing as to goods in either country.

2 – Any new arrangements “must avoid any diversion of trade”.

3 – It is essential that any new arrangements that are negotiated “do not constitute a border in the Irish Sea”.

4 – New arrangements “must give the people of Northern Ireland a say in the making of the laws which govern them”.

5 – They must result in “no checks on goods going from Northern Ireland to Great Britain or from Great Britain to Northern Ireland”.

The DUP does accept that checks that were in place before Brexit should continue and goods that are proceeding on from Great Britain, through Northern Ireland, to the EU may have different arrangements.

6 – They should “ensure no new regulatory barriers develop between Northern Ireland and the rest of the United Kingdom unless agreed by the Northern Ireland Executive and Assembly”.

7 – Seventh, they “must preserve the letter and spirit of NI’s constitutional guarantee set out most recently in the Belfast Agreement, by requiring in advance the consent of a majority of the people of Northern Ireland for any diminution in its status as part of the UK”.