During a breakfast presentation and question and answer session in Madrid on Tuesday morning, PSOE leader Pedro Sánchez attempted to untangle the Spanish Socialist Party's idea of Spanish nationhood in the 21st Century, after stating on Monday that "all nations are Spain".

"Is 'nation' a single concept or does it accept complexity? I am more in the latter camp", he mused: "Spain is a nation, it is not 'the Spanish state' as some [separatists] refer to it".

The 1978 Spanish Constitution recognises the "indivisible unity of the Spanish nation" but also the "autonomy of the nationalities...