Support for independence is falling in Catalonia, but it could still happen if opponents don’t vote.

A comprehensive survey of public opinion conducted every four months for the regional government found that only 41 percent of Catalans want to break away from Spain.

But those voters are more motivated to turn out.

Undecideds

By contrast, 11 percent don’t know if and how they are going to vote in the referendum, which the regional government intends to hold in September.

Another 18 percent say they will abstain.

If both groups stay home, the separatists would prevail with 62 to 38 percent of the votes.

More autonomy

The survey shows that support for independence surged in 2010, when Spain’s Constitutional Court annulled parts of Catalonia’s autonomy statute and the whole country was in economic crisis.

Since the economy started to improve in 2014, support for independence has come down from a high of 48.5 percent.

62 percent of Catalans do still feel the region doesn’t have enough autonomy.

But the picture gets murkier when they are asked how they would design Catalonia’s relationship with the rest of Spain.

Given four options, only 35 percent pick independence. 30 percent are content with the status quo, 22 percent want the region to become a federal state of Spain (with more autonomy) and 5 percent want less autonomy.