Barcelona is a city draped in flags. Only a handful of windows surrounding my rented apartment in El Born – a fashionably ramshackle district close to the harbour – are flag-free. From the rest hang esteladas, the distinctive blue-and-white-starred symbol of Catalan national sovereignty.

Catalonia has become increasingly polarised in recent years as requests for enhanced autonomy – consistently rejected by Madrid – have hardened into demands for outright independence from Spain. Polls suggest as many as 45 per cent of Catalans support secession, while 25 per cent favour federalism and a further 20 per cent support the constitutional status quo.

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