300,000 French people are permanently settled in the British capital city. They do not form a monolitic community, but various social groups marked by differences in economic and cultural capital. The French state has developed a strong institutional presence to meet the needs of this London based diaspora (consular services, cultural institute, schools, business support). The system is supplemented by associative structures that provide social services. French Londoners also have their own political representation: members of the French parliament, consular advisers, members of the Advisory Committee of the Union of French Nationals Abroad. These mandates give rise to elections and an extraterritorialisation of French politics. Brexit obliges the French Londoners—who have retained their French nationality—to consider the future of their resident status. They will have to negotiate with the British State. The new migration policies of the United Kingdom will also make the possibility to settle in London more difficult for French citizens.

Published in the context of Brexit, this research paper analyses the ‘double relationship’ between Britain and Europe: being ‘in’ by taking part in co-operation with other European states, and at the same time being ‘out’ by staying away from or even leaving multilateral programmes in Europe. This dilemma is worked on from the case of defence procurement policy. How does the British government decide to be both ‘in’ and ‘out’ of Europe by participating in the A400M military transport aircraft programme and withdrawing from the EuroMale UAV programme? Based on exclusive data, the decision in favour of the A400M (‘in’) is explained by the action of political, administrative and industrial actors who perceive the A400M as a ‘truck’ rather than a ‘race car’. As for the British State’s decision not to participate in the EuroMale programme (‘out’), it is conditioned by a weakening of the political will of political actors, and at the same time by a strengthening of conflicting relations between French and British administrations and industries. In doing so, this research contributes to the literature on the acquisition of armaments in strategic studies, and to the literature on differentiated integration in European studies.