Supreme Court denies government appeal in landmark ruling on Article 50

Published on 24th Jan 2017

The final verdict has been delivered: on 24 January 2017, the Supreme Court upheld the High Court’s decision that the UK government cannot rely on the royal prerogative and must get approval from Parliament before triggering Article 50 of the Treaty on European Union.

After a hard-fought battle that saw some of the country’s leading constitutional minds go head to head, a summary of the judgment was read aloud at 9.30am by Lord Neuberger, President of the Supreme Court.

In an historic decision, by a majority of eight to three, the Supreme Court dismissed the government’s appeal and found that an Act of Parliament would be needed for Article 50 to be triggered.  In a judgment that will be pored over by constitutional lawyers and political commentators alike, the judges emphasised that the giving and taking away of rights in the UK can be done only by Parliament, or with Parliament’s sanction.  Parliament had not given the government the power to take action, in the form of leaving the EU, which would have removed important rights for UK citizens.

As a result, the government will now need to pass an Act of Parliament authorising the triggering of Article 50.

Background to the appeal: a recap

This case was the government’s appeal from the High Court’s decision in November 2016 that the government could not rely on the ‘royal prerogative’ to trigger Article 50 without authorisation by Parliament.

Given both the significance and the urgency of the matter, the appeal ‘leapfrogged’ the Court of Appeal to be heard in the Supreme Court in December 2016, in front of all 11 of the Supreme Court judges.

What did the Supreme Court decide?

The majority of the Supreme Court judges were not persuaded by the government’s argument that the entry and exit from international treaties is a function that is reserved for it under the prerogative, and that Parliament would need to have expressly curtailed this right if it did not want the government to have the power to withdraw from the treaties constituting the EU.

The leading judgment, delivered by the eight judges who decided against the government, found that although the power to make and unmake international treaties was generally reserved for the executive, this applied on the basis that such treaties were not governed by UK law, and did not affect UK law or any rights or obligations under national law.

The majority judgment focussed on the European Communities Act 1972 (ECA), and in particular section 2, which the judges referred to as a “conduit pipe” that had opened up a new source of domestic law in the UK, flowing from the EU.  While the majority accepted that the law imported through section 2 would vary dependent on EU treaties entered into by the government, it did not follow that the ECA contemplated the government withdrawing altogether from the treaties establishing the EU.  On the contrary, the judges found that the ECA gave effect to the UK’s membership of the EU in a way that was inconsistent with an exercise by the UK government of prerogative powers so as to withdraw from the EU.  Or, put another way, the government had the power to alter what was coming through the conduit pipe but could not, without Parliament’s approval, turn off the pipe.

The judges stressed that it would have been possible for Parliament to have given the government that power.  But clear language would have been needed to do this. The ECA did not contain such clear wording to this effect.  Instead, particularly given its special status as a “constitutional” statute, the ECA provided the opposite.  It was an Act that provided for the UK to join the EU.  The exercise of the prerogative to leave the EU would be contrary to this aim, so could not be read in as being a provision of the ECA.

The effect of the referendum

The majority also rejected the argument that the 2016 Referendum Act had provided for Article 50 to be triggered without consulting Parliament.  The judges drew a contrast with legislation enabling other referendums, such as the 2011 referendum on alternative voting, which provided expressly for the consequences of the vote.  In the absence of any express provisions as to the effect of the referendum, a change of law required as a result of the vote “must be made in the only way in which the UK constitution permits, namely through Parliamentary legislation.”

Devolution not a barrier

While the government will have been disappointed (if not entirely surprised) to have lost the main argument in this case, it will gain some comfort in the unanimous rejection by the Supreme Court of the arguments that had been raised on devolution.

The essential question for the Supreme Court, raised in a reference by the High Court of Northern Ireland and accompanied by submissions from the Advocate General of Scotland and the Counsel General of Wales, was whether devolution legislation or convention required the government to consult with the devolved administrations before it could trigger Article 50.  If this had been the case, it would have made it far more difficult for the government to achieve its objective of triggering Article 50 by the end of March 2017.

The judges all agreed that the UK government is not constrained by the devolved administrations.  The judges considered the “Sewel Convention”: that the UK government would not normally legislate on devolved matters, which had extended in many instances to other matters affecting the competence of devolved administrations.  However, whatever the precise nature of the convention, the judges stressed that:

the policing of its scope and the manner of its operation does not lie within the constitutional remit of the judiciary“.

What happens next?

The Prime Minister, Theresa May, has promised to trigger Article 50 before the end of March. Following the Supreme Court’s decision, the government needs Parliament’s approval before any further steps can be taken.

Primary legislation will now have to be passed in Parliament.  Although Labour has indicated that it will not look to block the triggering of Article 50, this could offer in both Houses the opportunity to push the government for greater scrutiny over the Brexit negotiations.  The government is likely to look to keep the form of legislation very simple, though, and will be encouraged by comments in the majority judgment that suggests that this would be a constitutionally valid approach: “[t]here is no equivalence between the constitutional importance of a statute, or any other document, and its length or complexity.”

This result might not take the government by surprise. Politically, things seem to have moved on since the High Court decision, with the Prime Minister agreeing last week that both houses of Parliament would be given a vote on the final Brexit deal. It remains to be seen exactly how the Supreme Court’s decision will be woven into the political fabric, though it certainly cannot be ignored.

One for the history (and practitioner) books

This decision sees the end of one of the most publicised UK cases of modern times. Much as the referendum was an exercise in democracy, this decision was a reminder of the importance of the rule of law and the roles that Parliament and the courts have within that democratic system. Parliament’s approval is required as a matter of law before the government can give notice under Article 50.  But aside from that, as Lord Chief justice Neuberger explained, it’s a political matter now, and it’s over to the politicians to deal with the UK’s exit from the EU.

Whilst the case confirms a number of important points of constitutional law, it is also a model case for what can be achieved in a dispute when parties focus on just the key issues in debate and work together cooperatively on procedural issues. Its exceptional turnaround time of just over 6 months, from gestation to the final Supreme Court decision, shows what can be achieved in terms of efficient case management and sets a high standard to aspire to in other more run-of-the-mill cases.

Interested in hearing more from Osborne Clarke?


* This article is current as of the date of its publication and does not necessarily reflect the present state of the law or relevant regulation.

Connect with one of our experts

Interested in hearing more from Osborne Clarke?