Brexit is the term given to the exit of the United Kingdom from the European Union following the EU Referendum of 2016 in which the British electorate decided in favour of leaving the EU. The term is a portmanteau of the words "British" and "exit."
The default legal position, in accordance with English Law, which applies also in Wales, and also in Scots and Northern Irish Law, devolution notwithstanding, is that the United Kingdom will leave the European Union on 31st October 2019. This position applies throughout the British Isles where Westminister has jurisdiction over matters of international relations, except for the Isle of Man, which was never a member of the EU.
The default position has been challenged by Parliament by the passing of a private member's bill introduced by opposition Labour Party MP Hilary Benn which causes the government of the United Kingdom to be in breach of the law should it fail to deliver a deal with the EU on future EU-UK relations before leaving the EU.
The Benn bill requires the executive to deliver a letter requesting an extension of UK membership to the President of the European Council if either parliament will not countenance leaving without a deal and no deal can been reached by a deadline of 19th October 2019.
As a result of the private member's bill, the Prime Minister of the United Kingdom is legally bound to deliver either a deal, an extension to EU membership, or a convincing argument that the EU will not enter into a deal, by 19th October 2019. This is to give time for Members of Parliament to voice their concerns on the matter of leaving the EU and its consequences for the UK economy, and to seek an orderly exit from the EU as soon as possible.
The UK government's position is that the Benn ruling shall be tested to the limit. There is a suggestion that Prime Minister Boris Johnson may write to the European Council to satisfy the requirement, merely as a technicality, and then pursue a timely exit without a deal anyway, with or without the support of parliament.
Prior to the passing of the Benn bill, the role of parliament in the decision making over withdrawal had already been strengthened by the legal case brought and won by businesswoman Gina Miller which called for the government to seek the permission of parliament before enacting the law that would ultimately see the country leave the EU. With this legal precedent, parliament itself eventually took back control over the process from the executive, with Benn's more recent intervention being the latest intervention to prevent a disorderly withdrawal and all the problems that may entail.
Despite parliament's continued vigilance in safeguarding economic and political security in European relations, the government has nevertheless been accused of abusing parliament's statutory apparatus to further its own ends. As a matter of course, as in all Western democracies, the apparatus of state has been developed purposely into a non-political means of serving the everyday functioning of the state.
It is alleged that the government has sought to circumvent the role of parliament in passing the laws which govern progress and development in national life and international relations in the case of EU withdrawal. For example, the proroguing of parliament on 10th October 2019 for a period of five weeks is seen by many as a cynical attempt by the executive to force the hand of sovereign powers at home and abroad to accept a no deal outcome in order to bring about this default outcome on 31st October 2019, preventing any further extension of EU membership designed to bring about a deal.
In the light of the prorogation, which was granted by prerogative and given ascent by the queen, several protests alleging unconstitutionality were lodged at courts throughout the isles by parties seeking an orderly exit from the EU. Two of these cases had originally been dismissed- at the High Courts of England and Wales and of Scotland- though the Scottish court later ruled the prorogation illegal after a court of session concluding 11th September 2019. The third case is ongoing at the High Court of Northern Ireland in Belfast.
There is a legal challenge ongoing at a foreign court, brought by foreign interests, that alleges that the government is now in breach of the country's international treaties under articles 2 and 7 of the Treaty of the European Union concerning standards for rule of law and fundamental rights. However, it is clear that the British position is to leave the European Union anyway, in a timely fashion, and as such any foreign interventions shall not hold weight.
Politically, the British establishment has become embroiled in a heated debate about the constitutionality of the prorogation of parliament, with prominent figures such as Speaker John Bercow calling the move unconstitutional.
On 24th September 2019, the Supreme Court of the United Kingdom found that Boris Johnson had acted unlawfully in proroguing parliament. This is of great constitutional significance.