With so many opinions, articles and notes going around in respect of Brexit, I believe it would be useful to clarify a few constitutional points in the event that the result of the referendum of 23 June next will be “Leave”:
1. From a strictly legal point of view, the referendum does not repeal or abolish any existing legislation. It has only an advisory value under the EU Referendum Act 2015. Therefore, although politically the Government will certainly take into account the results of the referendum, the legal position grants the Government the freedom to ignore the results of the referendum.
2. The process of severance from the EU will only start when a formal notice is given by the British Prime Minister to the European Council in accordance with art. 50 of the Treaty on the Functioning of European Union (TFEU) (“Notice”).
3. Once the Notice is given, the clock will start ticking and a maximum period of two years (“Notice Period”) will run during which the UK will remain a Member State and will have to negotiate the terms of a withdrawal agreement with the European Union. For the withdrawal agreement to be finalised the draft has to be approved first by the European Parliament by simple majority vote and second signed by the European Council, if so approved by qualified majority vote or unanimity depending on the nature of the provisions in the agreement.
4. Once the Notice is given it cannot be withdrawn (there is no provision to this effect in art. 50 TFEU). Should the United Kingdom wish to change its mind, it needs to make a fresh application (pursuant to art. 49 TFEU) as any other applicant State wishing to join the EU.
5. On the expiry of Notice Period, the United Kingdom will no longer be a Member State, and the TFEU will cease to apply to it even if the terms of the withdrawal agreement have not yet been agreed. In theory, it is possible to apply for an extension of the Notice Period, however this would need to be approved by unanimous vote from the remaining 27 Member States.