This is how the UK could rejoin the EU – and the sacrifices they would probably demand from us

Fiona de Londras
British ambassador to the EU, Sir Tim Barrow delivers the official notice under Article 50 of the Lisbon Treaty to European Council President Donald Tusk in Brussels, Belgium: EPA

Divorces are rarely clean breaks. The parties remain connected emotionally, culturally, and sometimes financially for many years to come. In some cases, they even remarry, remote as that possibility may have seemed at the time of the decision to part.

The relationship between the UK and the EU was never a marriage, of course, but the analogy is not entirely unwieldy. Even after Brexit, the UK will have a close and continuing relationship with the EU, most likely under the terms of a comprehensive “Brexit deal”. However, there are some murmurings of the UK potentially rejoining the EU at some point in the future. Remote as this possibility might be, it is certainly possible.

Should the UK at any point wish to rejoin the European Union, it would need to make an application to do so, the same as all other non-member states. In the normal course of events, a state must show it meets the criteria for membership, at which point a long process of “accession” begins. However, as a former member state, the likelihood is that the UK would easily demonstrate its readiness of membership, at least across many of the key areas such as having a free market economy, a strong democracy, and adherence to the rule of law. This is not to suggest that there wouldn’t be stumbling blocks, however, and two can readily be imagined.

The first is the euro. Ordinarily new member states of the European Union are expected to adopt the euro and to join the currency union. The UK, of course, opted out of that, however it might not be quite as easy to resist the Euro on re-admission.

The strength of the UK’s case for not joining the euro is, of course, the importance of sterling and of currency autonomy to the City of London and to a strong UK economy, with resultant off-shoot benefits for the European Union itself. However, if the UK’s departure were to accelerate the “ever closer Union”, it may be difficult to convince all other member states (which would have to consent to membership) to accept divergences from the common approach.

A similar challenge can easily be foreseen in relation to the Schengen area: an area of common travel across 22 of the 28 member states. On this, the UK is perhaps more likely to be able to negotiate an opt-out, not least because Ireland (with which the UK already has a separate common travel area) is also outside of the Schengen zone. However, the UK might find itself under some pressure to revisit its earlier position.

This reflects a key point about any potential readmission: the UK would be applying and trying to negotiate admission in an incomparable position to the one in which it secured its current opt-outs from certain EU laws and policies. As a member of the European Union, the UK had a veto on all treaty changes: all member states do. Thus, in order to make progress on the desired law or policy, it was often sensible for the other member states to agree to allow the UK (and, indeed, other states) to opt out of certain laws or policies.

However, as an applicant, the UK would be in no such position. New member states are expected to be willing to, and to actually, adopt all EU laws. Although practicality demands that many of the UK’s laws will still be consistent with EU law, even after the Great Repeal Bill, these “gaps” will need to be addressed.

Other recently joined states will rightly be sceptical of special pleading to exempt the UK from these basic expectations, and may not be willing to make concessions that would put the UK back in the position in which it left the EU. The UK might well be put on a fast track to membership if it were to reapply, but that should not be mistaken for one in which too many exceptions from the normal expectations would be made.

Fiona de Londras is the Professor of Global Legal Studies at Birmingham Law School