The High Court has heard 3 days of argument in legal proceedings brought by a group of individuals seeking to determine whether the UK Government has the legal power to trigger the Article 50 of the Treaty of the European Union process to leave the EU without an Act of Parliament. A number of British citizens are suing the Government claiming that leaving the European Union will deny them rights derived from the treaties of the European Union which have been given force in UK law under the European Communities Act 1972, which they claim can only be removed by an Act of Parliament. Lawyers for the claimants also argue that leaving the European Union will amend Scotland’s separate system of law, which again they say can only be amended by an Act of Parliament. The Government argues that the result of the referendum on 23 June gave it a mandate to begin the exit, and that it has the power to trigger Article 50 under royal prerogative without a vote in Parliament. Appearing for the Government, the Attorney General Jeremy Wright argued that triggering Article 50 was a classic example of the proper and well-established use of the royal prerogative by the executive. The Government argues that Parliament did not take the opportunity to prevent a restriction on the use of royal prerogative for the triggering of Article 50, and that there is no inevitability that individuals will lose EU rights as that will be a matter for negotiation. The legal arguments are complex, raising thorny principles of constitutional law. However, the 3 day hearing did raise some interesting points:

• Lawyers for both sides are proceeding on the basis that the triggering of Article 50 is irrevocable, although the president of the European Council Donald Tusk said last week that the UK could still abandon the formal departure process after giving notice under Article 50.
• Attorney General Jeremy Wright, representing the UK Government, told the court it is “very likely” MPs will be able to vote on the final Brexit agreement between the UK and the European Union.
• James Eadie QC, representing the UK Government, told the court that EU citizens living in the UK will not automatically lose the right to remain in the country at the end of the Brexit process, since the right to reside in the UK is enshrined in national law.

Lord Chief Justice Lord Thomas, Master of the Rolls Sir Terence Etherton and Lord Justice Sales reserved their decision last Tuesday at the end of the 3 day hearing but said that judgment would be given as quickly as possible. It is likely that, whatever the outcome of the High Court hearing, the case will be appealed to the Supreme Court, with a hearing expected to take place in early December.