Why Brexit Poses an Existential Issue for Gibraltar

Just as the U.K.’s exit from the European Union poses challenges for the Irish border, it may complicate life on and around Gibraltar. The rocky outcrop at Spain’s southern tip has been British territory for 300 years, and its 2.2 billion pound ($2.9 billion) services economy relies on frontier workers coming from Spain for about half of the labor force. As the EU and the U.K. sealed their divorce, Spain sought guarantees that it will have a decisive say in any talks on the future of Gibraltar.

The 6.8 square-kilometer enclave is a self-governing British overseas territory, like Bermuda or the Falklands Islands. As such, most of its 34,000 residents are British citizens, who voted almost unanimously in a 2002 referendum to remain under sole British sovereignty. At the same time, Gibraltar is physically part of Europe’s mainland, with deep ties to neighboring Spain -- which questions the legal basis of the U.K.’s claims to the territory ceded to Britain under the 1713 Treaty of Utrecht, which ended the War of the Spanish Succession between European powers led by England and France. In the 2016 Brexit referendum narrowly won by anti-EU forces, 96 percent of Gibraltarians voted in favor of remaining in the EU.