A legal challenge in Belfast High Court that argued the UK government's Brexit strategy will damage the Northern Ireland peace process has been dismissed.

Lord Justice Bernard McCloskey delivered his ruling on three joined cases against British Prime Minister Boris Johnson's handling of the UK's European Union exit.

The trio of challenges contended that a no-deal Brexit on 31 October would undermine agreements involving the Irish and UK governments that were struck during the peace process and which underpin cross-border cooperation.

The UK government rejected that contention during two days of legal proceedings in the High Court.

In his written ruling, the judge said: "I consider the characterisation of the subject matter of these proceedings as inherently and unmistakably political to be beyond plausible dispute.

"Virtually all of the assembled evidence belongs to the world of politics, both national and supra-national.

"Within the world of politics the well-recognised phenomena of claim and counterclaim, assertion and counter-assertion, allegation and denial, blow and counter-blow, alteration and modification of government policy, public statements, unpublished deliberations, posturing, strategy and tactics are the very essence of what is both countenanced and permitted in a democratic society."

Co-applicant Raymond McCord

Lord Justice Bernard McCloskey said he considered the action was "doomed to failure". 

One of the applicants, Raymond McCord, whose son was murdered by loyalist paramilitaries in 1997, was in court for the hearing.

Through his lawyer, he conveyed his disappointment to the judge but thanked him for how he dealt with the case.

Unlike Brexit-related challenges heard in England and Scotland, the Northern Ireland cases are not be able to leapfrog straight to the UK Supreme Court following the High Court judgment, they will first have to be heard by the Court of Appeal in Belfast.

The Court of Appeal has confirmed it will consider any appeals tomorrow.

In anticipation of appeals, Mr Justice McCloskey said it will conduct a case management review this afternoon.

If an appeal is rejected, the case could then go to the UK Supreme Court in London alongside Scottish and English cases next Tuesday.

Additional reporting Vincent Kearney