A court challenge over a Stormont vote on extending post-Brexit trading arrangements for Northern Ireland has been dismissed, and the Assembly debate will go ahead as planned on Tuesday.

Ruling on Monday after an emergency hearing at Belfast High Court, judge Mr Justice McAlinden rejected loyalist activist Jamie Bryson’s application for leave for a full judicial review hearing against Northern Ireland Secretary Hilary Benn.

The judge said Mr Bryson, who represented himself as a personal litigant, had “very ably argued” his case with “perseverance and cogency”, and had raised some issues of law that caused him “some concern”.

However, he found against him on the three grounds of challenge against Mr Benn.

Mr Bryson had initially asked the court to grant interim relief in his challenge to prevent Tuesday’s democratic consent motion being heard in the Assembly, pending the hearing of a full judicial review.

However, he abandoned that element of his leave application during proceedings on Monday, after the judge made clear he would be “very reluctant” to do anything that would be “trespassing into the realms” of a democratically elected Assembly.

Mr Bryson had challenged Mr Benn’s move to initiate the democratic consent process that is required under the UK and EU’s Windsor Framework deal to extend the trading arrangements that apply to Northern Ireland.

The previously stated voting intentions of the main parties suggest that Stormont MLAs will vote to continue the measures for another four years when they convene to debate the motion on Tuesday.

After the ruling, Mr Bryson told the court he intended to appeal to the Court of Appeal. Any hearing was not expected to come later on Monday.

In applying for leave, the activist’s argument was founded on three key grounds.

The first was the assertion that Mr Benn failed to make sufficient efforts to ensure Stormont’s leaders undertook a public consultation exercise in Northern Ireland before the consent vote.

The second was that the Secretary of State allegedly failed to demonstrate he had paid special regard to protecting Northern Ireland’s place in the UK customs territory in triggering the vote.

The third ground centred on law changes introduced by the previous UK government earlier this year, as part of its Safeguarding the Union deal to restore powersharing at Stormont.

He claimed that if the amendments achieved their purpose, namely, to safeguard Northern Ireland’s place within the United Kingdom, then it would be unlawful to renew and extend post-Brexit trading arrangements that have created economic barriers between the region and the rest of the UK.

In 2023, the UK Supreme Court unanimously ruled that the trading arrangements for Northern Ireland are lawful.

The appellants in the case argued that legislation passed at Westminster to give effect to the Brexit Withdrawal Agreement conflicted with the 1800 Acts of Union that formed the United Kingdom, particularly article six of that statute guaranteeing unfettered trade within the UK.

This is a political argument masquerading as a point of constitutional law and the court should see that for what it is

The Supreme Court found that while article six of the Acts of Union has been “modified” by the arrangements, that was done with the express will of a sovereign parliament, and so therefore was lawful.

Mr Bryson contended that amendments made to the Withdrawal Agreement earlier this year, as part of the Safeguarding the Union measures proposed by the Government to convince the DUP to return to powersharing, purport to reassert and reinforce Northern Ireland’s constitutional status in light of the Supreme Court judgment.

He told the court that it was “quite clear” there was “inconsistency” between the different legal provisions.

“That inconsistency has to be resolved – there is an arguable case,” he told the judge.

However, Dr Tony McGleenan KC, representing the Government, described Mr Bryson’s argument as “hopeless” and “not even arguable”.

He said all three limbs of the case had “no prospect of success and serve no utility”.

He added: “This is a political argument masquerading as a point of constitutional law and the court should see that for what it is.”

After rising to consider the arguments, Justice McAlinden delivered his ruling shortly after 7pm.

The judge dismissed the application on the first ground around the lack consultation, noting that such an exercise was not a “mandatory” obligation on Mr Benn.

On the second ground, he said there were “very clear” indications that the Secretary of State had paid special regard to the customs territory issues.

On the final ground, Justice McAlinden found there was no inconsistency with the recent legislative amendments and the position stated in the Supreme Court judgment.

“I don’t think any such inconsistency exists,” he said.

He said the amendments were simply a “restatement” of the position as set out by the Supreme Court judgment, and only served to confirm that replacing the Northern Ireland Protocol with the Windsor Framework had not changed the constitutional fact that Article Six of the Acts of Union had been lawfully “modified” by post-Brexit trading arrangements.

“It does no more than that,” he said.

The framework, and its predecessor the NI Protocol, require checks and customs paperwork on goods moving from Great Britain into Northern Ireland.

Under the arrangements, which were designed to ensure no hardening of the Irish land border post-Brexit, Northern Ireland continues to follow many EU trade and customs rules.

This has proved highly controversial, with unionists arguing the system threatens Northern Ireland’s place in the United Kingdom.

Advocates of the arrangements say they help insulate the region from negative economic consequences of Brexit.

A dispute over the so-called Irish Sea border led to the collapse of the Northern Ireland Assembly in 2022, when the DUP withdrew then-first minister Paul Givan from the coalition executive.

The impasse lasted two years and ended in January when the Government published its Safeguarding the Union measures.

Under the terms of the framework, a Stormont vote must be held on articles five to 10 of the Windsor Framework, which underpin the EU trade laws in force in Northern Ireland, before they expire.

The vote must take place before December 17.

Based on the numbers in the Assembly, MLAs are expected to back the continuation of the measures for another four years, even though unionists are likely to oppose the move.

DUP leader Gavin Robinson has already made clear his party will be voting against continuing the operation of the Windsor Framework.

Unlike other votes on contentious issues at Stormont, the motion does not require cross-community support to pass.

If it is voted through with a simple majority, the arrangements are extended for four years. In that event, the Government is obliged to hold an independent review of how the framework is working.

If it wins cross-community support, which is a majority of unionists and a majority of nationalists, then it is extended for eight years.

The chances of it securing such cross-community backing are highly unlikely.