This note deals with the operation of Article 50 of The Treaty of the European Union (also known as The Lisbon Treaty) and the complexities involved in unravelling EU law from domestic law following the decision to leave the EU in the Referendum yesterday.

Article 50 provides that "Any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements."

The EU Referendum

In theory the outcome of the referendum does not bind the government. Having regard to the political climate, however, and the resignation this morning of David Cameron as Prime Minister, it is clear that the UK will leave the EU.

Mr Cameron said:

"The will of the British people is an instruction that must be delivered".

Article 50 requires a departing Member State to serve notice on the European Council of its intention to exit the Union and then to negotiate a withdrawal agreement with the Union.

Mr Cameron has said that notice will not be served until a new Prime Minister is in place, which will be in October this year. Assuming the government does then serve notice on the European Council, the treaties of the European Union will cease to be applicable to the UK from the date of the withdrawal agreement or, failing that, within two years of the notification unless we and the Council both agree to extend this period. The agreement is concluded on behalf of the Union by the Council and will set out the arrangements for withdrawal, including a framework for the UK's future relationship with the Union. Should the UK seek to rejoin the European Union, it would be subject to the same conditions as any other applicant country.

Effect on UK Law

The process of unravelling EU law from domestic law will be complicated. Repeal of the European Communities Act 1972 in itself would be insufficient.

In particular, subject to the nature of the terms agreed for the UK's exit, it seems unlikely that all EU law will be sought to be repealed. Much of it will be retained. In that event constitutional difficulties might arise. It is questionable, for example, whether a single 'Henry VIII' clause (allowing primary and secondary legislation to be amended or repealed by statutory instrument) will be constitutionally acceptable given the wide areas that EU law cuts across and the limited Parliamentary scrutiny that subordinate legislation allows. In any event, until repeal, all EU law which forms part of UK law will remain in force.

There will also be some difficulty in identifying the continuing status of EU law. Questions of interpretation will be likely to arise and have to be legislated for or else decided by the courts as to the precedent value of European court case law and its status in areas where a particular area of EU law was sought to be preserved in a domestic context.

Linked issues of law arise in respect of the devolved governments and legislatures. The devolution Acts are phrased differently but each of them appear to contain EU law that has been devolved. It is therefore possible that Scotland, Wales and Northern Ireland will retain EU laws which concern devolved issues which England will not.

Freedom of movement

So far as EU citizenship is concerned, this is a status that is dependent on national citizenship but it confers rights different from and additional to those that derive from national citizenship. The right to free movement within the territory of the EU is the most significant in practice.

The EU citizenship right to free movement is incorporated into UK law by the European Communities Act 1972 and is transposed by domestic secondary legislation. EU citizenship rights in the EU treaties are directly effective; they do not require domestic legislation for effect.

The EU citizenship of British nationals will have no independent existence following Brexit but the same may not automatically be said of their EU citizenship rights. The legal position of the body of persons that are currently termed EU citizens who seek to rely on EU citizenship rights following Brexit will depend on: (i) the nature of the legal situation that replaces EU membership; and (ii) whether the individual in question is a UK citizen in the EU or an EU citizen in the UK.

What is clear is that the UK's withdrawal will inform UK politics and vice versa for some time. The terms of our exit from the EU will also define the impact of withdrawal on the movement of people, goods, capital and services across the EU. Until that process is complete, nobody knows what a post EU UK is going to look like.

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