Russia indeed spans both Europe and Asia but almost all Russians live in the European part and majority of all Russian history and culture happened or is linked

Russia indeed spans both Europe and Asia but almost all Russians live in the European part and majority of all Russian history and culture happened or is linked to Europe, not Asia. Similarly Turkey technically is also in Europe (small part of Turkish territory) but nobody seriously claims that Turkey is a European country based on this technicality. Another example would be Israel which technically is not in Europe but is considered to be more European than Middle Eastern. So the Brits not being European is not really such an outlandish claim. Especially that there is a growing tendency for 'European' to actually mean 'related to European Union' instead of its original, geographic meaning.