Tomas Sereda | Getty Images
Park Guell in Barcelona, Spain.
Under Article 155 of Spain’s constitution, Madrid has the power to intervene directly in the running of Catalonia’s regional government, forcing it to drop the vote and obey the law.
This could involve sending in the police or suspending the regional government’s ruling authority in the industrial region, which has its own language and capital city Barcelona. This is widely seen as a last resort move, however.
Catalans, like Spain’s other 16 autonomous regions, already have power over health and education spending. The region says the central government takes much more than it gives back under Spain’s complicated system of budget transfers.
This feeling contributed to a surge of pro-independence fervor during Spain’s worst years of recession at the beginning of this decade.
The pro-independence movement has lost support since Spain returned to economic growth. The last poll showed that 44.3 percent backed a split from Spain, while 48.5 percent want to continue with the status quo.
However, a majority of Catalans do want to hold a referendum on the question of independence, polls show.