An exiting member state has a strong interest to curb opportunities to fool its intention to exit. A palatable way of doing so is to retain nationality of the exiting state and EU citizenship: By having, or acquiring, multiple citizenship, by birth or by naturalisation, in the exiting state and in other member states that do not enforce a ban on multiple nationalities. Multiple nationalities may be the answer for many wishing to retain both residence rights in the UK and free movement in the Union. This is especially the case in Northern Ireland, which already has half a million Irish passport holders. Many people in the UK are Irish citizens by descent from parents or grandparents born in Northern Ireland or the Republic of Ireland. In some cases, in order to establish their citizenship, they will first need to enter their names on the register of foreign births. But for many people asserting their Irish citizenship, which has been dormant is simply a matter of applying for an Irish passport (Dzankic 2016).
After Brexit, UK residents with Irish and British citizenship will still be both UK and EU citizens. ‘In a future where the UK is proposing to close its borders to EU nationals, this issue [of double citizenship of many Irish] may become very controversial, as EU nationals are unlikely to benefit from similar ‘dual nationalities’ in large numbers (...) following a full Brexit’ (De Mars et al. 2016). Unsurprisingly, the House of Lords European Union Committee launched an inquiry into UK-Irish relations on 1st of September 2016. Under the banner of taking back control, the UK may be spurred to restrict pervasive (ab)use of multiple citizenships and/or to tolerate it only in some cases.
While any exiting State may have a strong incentive to penalise instrumental naturalisation and abuse of multiple citizenships, the case of the UK is particularly interesting since it has a tradition of tolerance in this regard. Following the 1948 British Nationality Act, multiple nationalities have been tolerated in the UK system: Since 1 January 1949 the voluntary acquisition of a foreign nationality did not automatically cause the loss of British nationality. It was in principle possible for an individual to retain British nationality, combined with citizenship of the Commonwealth and/or foreign nationality. British decolonisation allowed for multiple citizenships more often than not, with the exception of not promoting it systematically for territories claiming independence. If the country stays on its path, it will allow multiple citizenship, permitting some people to effectively be British and European citizens at the same time.
Generally, in former British territories that achieved independence, the provisions dealing with the consequences for nationality had a recurring theme: The person who became a national of the newly independent State under its initial laws, would cease on that day to be a British citizen, with exceptions based on a connection with the UK or remaining British colonies (Fransman 2011, p. 607). Similar provisions can be found in the independence acts of the following British colonies: Uganda, Kenya, Gambia, Botswana, Lesotho, Malta, Trinidad & Tobago, Barbados, Guyana, Jamaica and Cyprus. If we look at nationality provisions in the Independence acts of countries such as the commonwealth country Nigeria, Ghana, the Malayan federation, Zambia or Malawi we recognise the same pattern: The question of who kept British nationality largely depended on whether one would acquire nationality of the newly independent state.
In keeping with this tradition, the UK ought not to oppose retaining of European citizenship on the part of the population that has ‘obvious ties’ to the EU.16 Were British citizens having ‘obvious ties’ to the EU somehow offered to maintain their prior status as EU citizens, the UK would need to break with its traditional tolerance in order to oppose it. The UK is not well-equipped to prevent instrumental use of multiple citizenships, but it still has some options that it might be tempted to use.
Given the focus on migration in the debate leading up to the referendum, an incentive for the UK could also be to harden its domestic immigration law, or seek to pick and choose which second country nationals it is willing to admit to residency or to naturalisation. This can be done by reforming nationality or immigration law, but there are more subtle ways of achieving this: For example, by sharpening requirements in citizenship tests17 to make naturalisation a harder option for low skilled EU migrants, or by raising fees for requiring indefinite leave to remain or for naturalising in the UK. Currently fees are very high and rising and it is unclear what costs for applicants we would be dealing with.
Conversely, the exiting member state may also choose to penalise instrumental naturalisation by its own nationals living in other member states. One option might be to re-introduce additional criteria, such as the requirement of ‘a genuine link’18 to strengthen one’s claim of having British citizenship; an option fully in line with international law. This option may lead to stripping of some rights but not of status civitatis as such since the UK does not impose lapse of citizenship because of residence abroad. However, it cannot be excluded that a revirement towards the genuine link doctrine of an exiting member state may implicate statelessness in cases in which the member state provides for loss of citizenship for those citizens who permanently reside in another state and who do not have another nationality to rely on. In ten member states citizens may lose nationality due to continuous residence abroad.19 Another option for penalising instrumental naturalisation of British citizens abroad would be making life difficult for UK nationals wishing to renounce to their original citizenship in order to naturalise in states of the Union that enforce a ban on dual nationality,20 for example, by raising fees and making it economically costly to renounce.
These incentives, and many others, would need to be resisted. During the two-year interregnum following an invocation of Article 50, the exiting member state would need to observe the limits imposed by European law on its ability to modify its own provisions on nationality and migration. Were the UK to modify its policy in ways incompatible with European law, it could be subjected to infringement procedure by the Commission and judicial review by the European Court of Justice. The policy adopted under the interregnum would also have practical implications once the UK has effectuated the exit from the Union.