Spain’s government borrowing costs also surged, while the euro drifted lower against the dollar as investors weighed fallout from the violent police crackdown on Catalans on Sunday. This morning local officials announced 90 per cent of those who voted in the contested referendum on Sunday, which Madrid deemed illegal, called for independence from Spain. Around 2.26 million people took part in the ballot, representing around 42.3 per cent of Catalonia’s 5.34 million voters.

GETTY Catalonia referendum: Spain’s stock market came under pressure after Catalans voted for independence

The northeastern region of Spain accounts for a fifth of the country’s economy and its tax returns are crucial to the national budget. Many analysts expect the crisis to be resolved with more autonomy, but some said the uncertainty could impact the Spanish government’s economic growth and soil Prime Minister Mariano Rajoy’s reputation. Federico Santi, an analyst at Eurasia Group in London, said the vote was “probably the worst outcome for Madrid”.

Catalan referendum: Brutality of Catalonia's referendum vote Tue, October 3, 2017 Scenes at the Catalan independence referendum Play slideshow AFP/Getty Images 1 of 17 People clash with Spanish Guardia Civil

It is clear that risks to government stability are increasing Federico Santi, an analyst at Eurasia Group in London,

He added: “There was violence but they didn't stop the vote either and public opinion in Catalonia is more polarised. "It is clear that risks to government stability are increasing." Spain’s mainstream political parties have largely backed Mr Rajoy’s opposition to the Catalonia independence referendum, but the prime minister faces criticism over his handling of the issue. Nearly 850 people were injured when police clashed with independence protesters on Sunday as officers in riot gear closed polling stations and used batons to stop voters from reaching the ballot boxes.

GETTY Catalonia referendum: Spain’s government borrowing costs surged as investors weighed fallout