UK Legal Aspects
It is the departing state’s system of law which defines the terms on which the decision to leave is made. The European Union Referendum Act 2015 extended the franchise to those who ordinarily voted in elections to the House of Commons (which included UK Irish and nationals of Commonwealth countries. It did not extend to the several million EU citizens who had been living and working in the UK often for decades and who are eligible to vote in European Parliamentary elections. Equally, the legislation provided that UK nationals who had last registered to vote more than 15 years ago could not vote in the referendum.
The Brexit referendum was not stated to be legally binding even by the legislation which provides for it. In legal terms, it was an advisory referendum only. That said there was wide political acceptance of the principle that the referendum should be implemented. From a political and democratic perspective, Parliament had put the issue to the people for resolution, and the outcome should be respected at least unless and until reversed by another referendum.
Initially, the UK government proposed to give notice triggering Article 50 without Parliamentary authority. It justified this proposed course by the use of residual and inherent power of governments to act in international matters, an aspect of the so-called crown or executive prerogative. A legal case was taken by Gina Miller culminating in a decision of the UK Supreme Court which decided that approval by Parliament by statute was required to begin the process under UK law. They accepted that the effect of triggering withdrawal was to set a course to change UK laws fundamentally across a vast range of areas. The most basic principle of the UK constitution is that Parliament is sovereign so that its consent was needed to this fundamental change.
A brief piece of legislation the European Union Notification of Withdrawal Act 2017 was passed by an overwhelming majority in March 2017, authorising the Prime Minister to give notice of withdrawal. On 29 March 2017, the UK gave notice by letter to the European Council of the UK’s intention to withdraw from the European Union. This triggered a default exit date of 29th of March 2019 in the absence of an agreement between the EU and UK otherwise.
The parties in the Miller case and the court accepted without detailed argument, that the withdrawal request was irrevocable and that the terms of withdrawal could be made conditional. This argument suited the particular agenda of each party and was not a key issue in the case. There is a logic in finding notice to be irrevocable as otherwise, it would allow a state to give a withdraw notice for political gain.
However, there was always a considerable body of opinion that considered that the notice must be revocable in principle. The Vienna Convention on the Law of Treaties provides specifically that the notification to withdraw from a treaty may be revoked at any time before it takes effect.
The issue was the subject of litigation taken by a group of Scottish politicians and the Good Law Project which was referred to the Court of Justice of the EU. In December 2018 the Court of Justice decided that the notice to withdraw could be revoked by further notice, provided it was done before expiry, was unconditional and done in good faith.
Article 50 and a New Basis for Former EU Law
The effect of Article 50 is that in the absence of a Withdrawal Agreement or consent to an extension, the Treaties were to cease to apply as a matter of European Union law to the United Kingdom on 29th March 2019 (may also apply to new exit date on 31 December 2020) . The UK Parliament, as part of its so-called great repeal bill, the European Union (Withdrawal Act) 2018, set the date of Brexit at the same time as a matter of UK law.
Following the inability of the Theresa May government to ratify a Withdrawal Agreement made with European Union in November 2018 the withdrawal date was later extended from 29th of March 2019 to 10 April 2019 and again to 31 October 2019 (may also apply to new exit date on 31 December 2020).
The European Union (Withdrawal) Act 2018 continues European Union Law in force in force in the UK after the date the United Kingdom leaves the European Union, the pre-existing body of EU law which had become part of the law of the United Kingdom now rests exclusively on the basis of this new UK legislation. The Act provides extensive powers to change and modify the exiting and frozen body of European Union law, by orders in Council or other executive or ministerial order.
Significance of Change
The provisions of European Union law continue to apply only so far as supported by UK law after that date. The European Union’s institutions have no further law-making powers in relation to the UK. The European Court of Justice has no further role in interpreting and giving effect to the legislation. The supremacy of EU law in the United Kingdom ends.
After the enactment of the Withdrawal Act, EU legislation, in particular, that which has taken direct effects such as EU Regulations would be frozen in time on the date of withdrawal, and thereafter amended by the UK Parliament or more controversially and more likely by numerous orders made under the Act’s enabling powers.
After Brexit, the remaining body of law of former European Union Law has been given effect by the UK legislation. Many European Union laws will require repeal modification and amendment in the context of the Repeal Act. Many laws (and some rights) will cease to exist by reason of the UK leaving the EU.
Treaty rights which would require treaty amendment and the consent of all states of the European Union may be repealed by ordinary UK legislation. Rights conferred or confirmed by directives and regulations will be subject to repeal or amendment by the UK Parliament, rather than through the legislative procedure of the European Union usually involving the Council of Ministers and the European Parliament. Most European Union rights will be no longer available to UK citizens and will be no longer directly enforceable against other EU citizens in other states.
It may be that a new agreement is entered between the EU and UK which preserves or re-enacts most of these laws and rights in new modified terms. It may provide for its own institutions, to which recourse may (or may not) be had by private parties. It is likely that a direct right to assert the agreement will be limited to those with accrued rights (e.g. already living in each other’s territory) as opposed to those claiming a new right (e.g. to establish themselves in another state).
The European Union will cease to have jurisdiction, and UK citizens will cease to have recourse to both the main European Union institutions such as the Commission and the Courts of Justice but also to the myriad of other EU bodies in various fields such as the European Aviation Safety Agency, European Fisheries Control Agency, European Chemical Agencies and numerous others. The institutions, in particular, the Commission which enforces certain laws will no longer have jurisdiction or power in the UK so that the functions will be conferred on domestic UK bodies in their place.