A referendum is intended to take place today in the region of Catalonia is Spain over Catalan independence.

The referendum is being held according to the decision of Catalan leadership, and faces opposition from the Spanish government. The Spanish constitutional court has ruled that the referendum is illegal.

Residents of the region lined up at polling stations overnight to ensure that the stations indeed opened this morning, but it appears that the Spanish government is set on preventing the referendum from taking place.

In the past hour there are reports emerging from the Catalan capital of Barcelona that Spanish police have started closing polling stations in order to put a stop to the referendum.

Catalan President Carles Puigdemont, who supports a Catalan separation from Spain, said earlier that if the referendum saw a majority of “yes” votes, he would declare an independent Catalonia within 48 hours.

Earlier polls had indicated that a majority of Catalans do not support independence. Nevertheless, the Spanish government is not ready to recognize the legitimacy of the referendum by any means.

Although Philip the Great conquered Catalonia in the War of Spanish Succession in 1714, the Catalans refused to accept the change in status and were finally granted a short-lived national government in 1931, during a period of Spanish democracy. General Francisco Franco reconquered the region, murdering and exiling thousands in 1938, but a certain amount of autonomy was restored in 1977.

Catalonia is the industrial heartland of Spain, its center for trade in goods finance and hi-tech, and accounting for18.8pc of Spanish GDP, compared to 17.6pc from Madrid. Secession would therefore cost Spain almost 20 per cent of its economic output.

And that is without taking into account the loss of the Barcelona football team.