UK Supreme Court Rules Parliament Must Hold Vote on Article 50

January 24, 2017

1. The Supreme Court (the UK’s highest court) has ruled today that parliament must vote on whether the UK can start the process of leaving the European Union.  The Supreme Court held by a majority of eight to three that the UK government cannot trigger Article 50 – the official legal notification to the EU that the UK is going to leave the bloc – without an act of parliament authorising it to do so.  The landmark decision upholds a High Court ruling handed down last November. 
2. The UK government had argued that royal prerogative powers mean MPs do not need to vote on triggering Article 50.  The Supreme Court rejected this.  Withdrawal from the EU will fundamentally change the UK’s constitutional arrangements because it will cut off the source of EU law: "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."
3. The Supreme Court also ruled that UK ministers are not legally compelled to consult the devolved governments of Scotland, Wales and Northern Ireland before triggering Article 50.  The Supreme Court unanimously held that relations with the EU are reserved to the UK government and parliament, not to the devolved institutions.
4. The government’s parliamentary bill on Article 50 is likely to be very short.  Whilst MPs will probably be reluctant to ignore last June’s (non-binding) EU referendum result and block the bill, they may seek to impose additional conditions.  Labour leader Jeremy Corbyn has said his party would seek to amend it "to make demands on rights, protections and market access".  The SNP has vowed to put forward fifty "serious and substantive" amendments to the bill.
5. The Article 50 bill will be given an accelerated passage through both Houses of Parliament.  This means the Supreme Court ruling may not change the government’s timetable for triggering Article 50 by end March 2017 (so that the UK would be out of the EU by end March 2019).
6. If the government struggles to achieve parliamentary consensus, the Prime Minister could call an early general election to secure an electoral mandate for Brexit.
7. The Supreme Court did not give its views on whether the UK may change its mind on Brexit, even after triggering Article 50.  A legal challenge is expected to begin in the High Court in Dublin later this month to determine whether Article 50 can be withdrawn once invoked.  Tax barrister Jolyon Maugham and others are hoping the Irish courts will make a referral to the European Court of Justice on the issue.  If the ECJ was to rule that Article 50 is revocable, it would enable the UK to reject the outcome of Brexit negotiations should they not prove acceptable to parliament or voters, and remain in the EU.

The full judgment of the Supreme Court is here together with the court’s summary for the media.