Catalonia Referendum Threatens the Future of Spain

The regional government in Catalonia, a province in Spain, on Wednesday signed a decree scheduling a referendum on independence from the European country for October 1.

The debate over Catalonia's attempted secession is one of Europe's knottiest long-running political rows. Here's what you need to know ahead of the vote.

Why does Catalonia want independence?

Spain wasn't always a unified country; before the state was formed in 1492, Catalonia was part of a kingdom called Aragon. Even after Aragon was subsumed into the new Spanish nation, Catalonia had a large degree of regional autonomy and its own parliament, which lasted until its abolition by Philip V of Spain in 1714.

Later, during the early 20th century before the years of Francisco Franco's fascist dictatorship, Catalonia enjoyed some degree of self-government. Modern-day Catalonia has a parliament, a government, and some devolved powers.

Catalonia, which includes the city of Barcelona, also has a distinctive local culture. Its language, Catalan, is widely spoken alongside Spanish, and notable distinctions from the rest of Spain include the province's decision to ban bullfighting, seen elsewhere in the country as a totemic Spanish activity.

As a wealthy region with a strong tradition of private enterprise, Catalonia has traditionally provided large proportions of Spain's tax base, but nationalists complain that this has not reaped rewards, with public investment in the region too scarce.

How will the referendum work?

This vote will follow another in 2014, when the pro-independence side won by a large margin, but on a turnout so small the vote was not considered authoritative.

As in 2014, the Spanish government does not recognise Catalonia's right to hold a referendum. It accused the region's parliament of committing a "constitutional and democratic atrocity" on Wednesday when it passed the bill calling for the referendum.

That means there is a question mark over whether the referendum will happen at all. According to an analysis by Teneo Intelligence, there is a 70 percent chance of the Spanish government managing to stop the vote, for example by prosecuting Catalan politicians or ordering police to seize ballot boxes.

If the poll does go ahead, the pro-independence parties will want to attract a turnout greater than 37 percent, the figure last time, as well as a victory for independence. If they manage to do so, they will seek to paint the vote as legitimate.

What happens after?

If the vote does happen, the Catalan government has said its intention in the case of a successful outcome is to begin behaving as an independent state. It will start passing laws as such, even though each will inevitably be declared invalid by Spain's constitutional court.

Eventually a longer-term solution would have to be reached, and the Catalan government would hope to force the Spanish government into a negotiation on future terms.

If the Spanish government manages to halt the vote by removing ballot boxes, Marta Rovira, from the Catalan Republican Left party (the left-wing coalition partner in the region's left-right pro-independence government) has said that "we will mobilize the citizens to prevent that from happening," raising the possibility of mass civil disobedience.

Anyone who has visited Barcelona can attest to the myriad pro-independence flags and banners that adorn the streets even outside campaign time, suggesting such demonstrations could be huge and garner vast international attention.

But such disobedience may harm the calm, reasonable picture of the pro-independence case that Carles Puigdemont, the region's center-right president, has sought to paint.