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MADRID (Reuters) - Support for Catalonia’s independence from the rest of Spain has fallen to its lowest level since a separatist campaign gained traction in 2012, but still remains a close call ahead of an October referendum on secession, a survey showed on Friday.

Some 41.1 percent of people in Catalonia were in favor of the creation of an independent state, according to a June poll by the regional government’s Centre of Opinion Studies (CEO), down from around 44 percent recorded in March and December.

The number of people actively against separation from Spain also rose slightly to 49.4 percent in June from 48.5 percent in March.

Regional leader Carles Puigdemont is organizing a referendum on northeastern Catalonia’s divorce from Spain’s other 16 regions for Oct. 1, though the central government has said the plebiscite would be illegal and has vowed to block it.

The independence drive in the region, the most populous in Spain with its own language and a thriving industrial hub, has been gaining force since a deep national economic slump prompted local leaders to claim Catalonia would be better off alone.

Under Article 155 of the Spanish constitution, Madrid can directly intervene in the running of the region and force it to drop the vote which, potentially, would involve sending in the police or suspending the government’s authority to rule.

Direct intervention, however, is considered a last resort and confrontation between Barcelona and Madrid is more likely to descend into months of legal wrangling and a potential regional election.

Puigdemont has said that if the “Yes” vote wins in October, the regional government will declare independence within 48 hours. A “No” vote would prompt an early election.

The region’s previous non-binding poll in 2014 - which had a low turnout and was also ruled illegal by Madrid - saw 80 percent in favor of full secession.