Madrid: Political tension in Spain peaks this week in the countdown to a vote in Catalonia that could lead the region to declare independence, potentially breaking up one of Europe’s oldest countries.

The prospect of the rich northeastern region of 7.5 million people seceding from Spain has transformed the 27 September  election for the regional parliament into a battle for the country’s future.

Catalan nationalists are pitted against the Spanish government which has heavyweight backing from the likes of US President Barack Obama.

Pressure on Catalan regional president Artur Mas and his allies has mounted over the past two weeks, with banks, businesses and European leaders warning of the high stakes.

Madrid has blocked Mas from following Scotland’s example by holding a straight referendum on independence, so he has framed the regional election as an indirect plebiscite.

Obama, Cameron back Spain

Polls show pro-secession candidates could win a majority in the 135-seat Catalan parliament on next Sunday.

If they win, Mas has vowed to push through an 18-month roadmap to secession for the region, which accounts for a fifth of Spain’s economy.

Spain’s Conservative Prime Minister Mariano Rajoy has rolled out the big guns in response, securing the backing of several world leaders in his opposition to secession.

Obama and British Prime Minister David Cameron called for Spain to stay united, after Germany’s Chancellor Angela Merkel also backed Rajoy.

The European Commission reiterated its warning that Catalonia would drop out of the EU if it broke away from Spain. Mas claims that in practice the bloc would never let his region go.

Major Spanish and European banks have also joined the political fray, along with Catalan businesses, with both sectors breaking their long silence in the tense weeks leading up to the vote.

Commercial and saving banks associations warned that Catalonia’s secession would put at risk ‘financial stability’ and could drive them to abandon the region, causing a possible credit crisis.

Various economic lobbies have warned against secession, including Catalonia’s main business association Foment del Trabell, which said it could cause ‘enormous financing difficulties’.

Mas claims Madrid is orchestrating an intimidation campaign against independence. ‘But the more they mobilise, the more votes we pile up,’ he said Friday at a rally.

General election warm-up

The Catalan question fills countless newspaper columns—mostly anti-independence—and prompts television interviews with politicians and experts.

But the battle is also being fought on the ground, with Rajoy’s Popular Party (PP) canvassing in Catalonia, a region where it is largely unwelcome.

Rajoy has been criticised for going after Mas in the courts instead of negotiating with him, and for ignoring Catalan demands for greater fiscal powers.

The prime minister has not shifted his tough stance on Catalonia, but his PP party is campaigning hard there to stop voters defecting to a new political rival, the centre-right Ciudadanos party.

The Catalan vote will also be a gauge of Spain’s upcoming general election in which Ciudadanos and the left-wing party Podemos are mounting a strong challenge to Rajoy.

Like the PP, Mas’s CDC party has been hit by corruption scandals which have fuelled the rise of these two new forces, transforming Spain’s electoral landscape.

But Mas’s opponents are divided.

The main opposition Socialists are calling for a constitutional reform to answer Catalan demands.

Podemos is in favour of letting Catalans vote in a referendum on the issue but says Spain should reform itself in such a way that they would not want to leave.

Ciudadanos, polling in fourth place nationally, defends the unity of Spain.

‘We want to end this separatist campaign and put an end to this debate,’ said Ciudadanos leader Albert Rivera.

In next Sunday’s vote, he said, ‘there should not be winners and losers.’