Professor Kate Moss and Lynn Ellison, from the University of Wolverhampton’s Law School
Recently we blogged about the High Court ruling regarding the challenge to Theresa May’s ability to trigger Article 50 to leave the European Union under Prerogative power. http://www.wlv.ac.uk/about-us/news-and-events/academic-blog/2016/november-2016/brexit-article-50-and-some-old-chestnuts-constitutional-law-comes-to-life/
We mentioned then that the Government had appealed to the Supreme Court to try to overturn the decision. On January 23, 2017, the Court made the final ruling and we can now confirm what the decision was and how it will affect Brexit.
The Supreme Court upheld the original decision of the High Court, by a majority of eight judges to three, rejecting the Government’s appeal that the Prime Minister could trigger Article 50 on behalf of the Crown. Instead, the Court upheld the decision of the lower court that this should be a matter for Parliament as a whole to undertake.
The constitutional reason given for this decision was that whilst the prerogative gives the government the legal authority to change treaties it cannot act under prerogative powers to alter or affect citizens’ rights as enshrined in EU law. Specifically, “the change in the law required to implement the referendum’s outcome must be made in the only way permitted by the UK constitution, namely by legislation [and] the Supreme Court holds that an act of parliament is required to authorise ministers to give notice of the decision of the UK to withdraw from the European Union.'
The Court also confirmed that this does not mean that the devolved institutions in Scotland, Northern Ireland and Wales need to be separately consulted. It is a matter for the Westminster Parliament - which of course already includes representation of all the constituencies in all four countries of the United Kingdom.
As a result of this ruling, Jeremy Wright, the Attorney General, confirmed that the Government will “comply with the judgment of the Court and will do all that is necessary to implement it.” David Davis, the Secretary of State for Exiting the European Union (aka the ‘Brexit Secretary’) has already made a statement to Parliament indicating that the Government will publish an outline bill within days. It is likely that this bill will be very brief. PM Theresa May has now also stated that the Government will publish a White Paper (a document which outlines the Government’s proposals) giving details of the Government’s plans for leaving the EU.
Does this mean that we don’t have to leave the EU?
No, this does not mean that we are no longer going to ‘get a divorce’ from the EU. The process will still be started, but this judgment clarifies who has the authority to start it and the correct constitutional process by which that can be achieved.
Is this just a matter of unelected Judges telling us what to do?
No, this is a judgment of the Court which upholds the principle of Parliamentary Sovereignty – that in matters of great constitutional importance, where the rights of UK citizens will be affected, only Parliament, not Ministers, can take such a momentous decision. Gina Miller has said that the litigation only ever sought to clarify whether the government could use the prerogative to trigger Article 50 as a means of exiting the EU or whether Parliament, in its supreme law-making capacity, was sovereign in this matter. The decision of the Supreme Court therefore supports fundamental constitutional principles such as the rule of law, the separation of powers and Parliament’s role as the legal and political cornerstone of the UK constitution. This decision also goes some way to reassure us of the role of the courts in holding the Executive to account in a transparent way.
But we had a Referendum, surely that is enough?
No, because the referendum did not state what would need to happen in Parliament if we voted to leave. Because of this, when giving judgment, Lord Neuberger, the President of the Supreme Court, stated:
“Where, as in this case, implementation of a referendum result requires a change in the law of the land, and statute has not provided for that change, the change in the law must be made in the only way in which the UK constitution permits, namely through Parliamentary legislation. What form such legislation should take is entirely a matter for Parliament.”
The case reference is R (on the application of Miller and another) (Respondents) v Secretary of State for Exiting the European Union (Appellant)  UKSC 5
 Per Lord Diplock in the case of BBC v Johns  Ch.32