In a unanimous judgment, the High Court in London today ruled that Brexit may not be triggered by the UK's Secretary of State for Exiting the European Union (Liam Fox). In effect, the judgment says such a move requires a decision by Parliament.

The 32-page, 111-paragraph judgment was delivered by the Lord Chief Justice of England and Wales, the Master of the Rolls and Lord Justice Sales. It will now be appealed by the UK Government to the UK Supreme Court which is expected to hear the appeal on 7-8 December.

The judgment does not stop Brexit or overturn the referendum result. Instead, it means that – if to-day's judgment is upheld by the Supreme Court – that the decision to serve notice under Article 50 of the Treaty on European Union ("TEU") must be made by the UK's Parliament rather than by the Government or a Minister. The judgment reiterates the sovereignty, role and centrality of Parliament in such matters.

The Court stated in paragraph 4 that the "sole question in this case is whether, as a matter of the constitutional law of the United Kingdom, the Crown – acting through the government of the day – is entitled to use its prerogative powers to give notice under Article 50 for the United Kingdom to cease to be a member of the European Union."

The Court answered that question 107 paragraphs later as: "we hold the Secretary of State does not have power under the Crown's prerogative to give notice pursuant to Article 50 of the TEU for the United Kingdom to withdraw from the European Union".

The judgment was careful to say that the "court does not question the importance of the referendum as a political event" but confines its comments to "a pure legal point about the effect in law of the referendum".

The legal issues in the case now go to the Supreme Court but the political issues move to the centre stage of the political arena.