UK High Court Rules That Parliament Must Vote on Triggering Article 50 Process for Brexit

November 3, 2016

1. The UK High Court has ruled today that parliament must vote on whether the UK can start the process of leaving the European Union.  This means the UK government cannot trigger Article 50 – the official legal notification to the EU that the UK is going to leave the bloc – without parliamentary approval.
2. The government had argued that royal prerogative powers mean MPs do not need to vote on triggering Article 50.  The High Court rejected this, ruling that the rights given by parliament in the European Communities Act 1972 could only be taken away by parliament, not the government.  The UK does not have a written constitution but the court ruled that the government’s arguments were contrary to "fundamental constitutional principles of the sovereignty of parliament". 
3. The government has announced it will appeal.  The appeal will go straight to the Supreme Court (the UK’s highest court) and be decided before the end of this year.
4. The ruling is a blow to the government’s plans for Brexit.  The UK Prime Minister, Theresa May, announced last month that Article 50 would be triggered by end March 2017 (meaning the UK would be out of the EU by end March 2019).  This timetable is now in doubt.  If the High Court decision is upheld, the government will have to draft a bill on triggering Article 50 and place it before parliament.  The bill will then have to be debated and passed in both the House of Commons and the House of Lords.
5. It is thought highly unlikely that either house would block the bill.  Although the outcome of the referendum in June this year was, as a strictly legal matter, merely advisory, parliament would probably be reluctant to ignore the results.  But MPs – the majority of whom were in favour of the UK remaining in the EU – may impose conditions on the triggering of Article 50.  These conditions could include parliament being happy with the terms of any future deal.
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 High Court did not address another current question, whether an Article 50 notice can be revoked once given.  It is possible the Supreme Court may also give its views on whether the UK may change its mind on Brexit, even after triggering Article 50.  Some commentators, including Lord Kerr who was involved in the drafting of Article 50, have expressed the view that it can be withdrawn.

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