The High Court has ruled that a Parliamentary vote is required in order for the UK to trigger Article 50 and begin the negotiations to exit the European Unit. The Government lost the argument that a Parliamentary vote was unnecessary and that Article 50 could be triggered using the Royal Prerogative executive powers. This is an important judicial reassertion of what is commonly referred to as the keystone to the UK’s unwritten constitution- “Parliamentary Sovereignty” i.e. the supreme legal authority in the land is the legislature.

The crucial issue which appeared to guide the Court’s decision was that triggering Article 50 would be irrevocable and would mean certain of UK citizen’s domestic rights would be automatically extinguished. It is a clear principle of the UK’s constitution that the Government are incapable of acting in a manner that removes citizen’s domestic rights unless authorised to do so by an Act of Parliament itself.

With the Government indicating that they will seek permission to appeal this Decision to the Supreme Court, it is unlikely that we will get a final decision on this matter until January 2017 at the earliest. However, most legal experts are of the opinion that the judgment is correct and an appeal is highly unlikely to be successful.

Perhaps the most interesting aspect of this decision will be the political ramifications which arise from it. Put simply, Theresa May will be unable to pull the trigger without getting Parliament’s approval. An Act of Parliament can be pushed through quickly but then MPs and Peers sitting in the House of Lords will have to vote again on whether the UK should leave the EU. This will raise interesting questions regarding which way MPs will vote given there may well be a discrepancy between the Referendum result in their own constituency and their Party whip.

The UK Government is likely to be pressured in the meantime to reveal further details on its negotiating stance with the EU and/or plans for post-Brexit Britain, to enable Parliament to make an informed decision when voting on any primary legislation drafted for the UK to trigger Article 50. The only certainty would appear to be that there will be further delay in Article 50 being triggered and we shall have to wait and see how the financial markets react to this further development.