“This at least now provides an opportunity for Parliamentary and Assembly scrutiny of the issues around Brexit,” he said.
“This judgement is obviously going to be appealed by the Government. Notwithstanding the final outcome, it is clear they now need to spell out much more clearly what they intend Brexit to mean.
“In the event the Supreme Court rules there is indeed a vote required, it raises the issue of the need for a legislative consent motion in the devolved assemblies. It is now vital the Executive takes its own legal advice on this as a matter of urgency.
“Ultimately, Brexit has such fundamental implications for the UK and Northern Ireland, it would be perverse if decisions regarding the formal triggering of Article 50 were not subject to the most detailed scrutiny and accountability.”