MADRID—The parliament of Spain's powerful northeastern region of Catalonia has approved a largely symbolic declaration stating the region is a sovereign entity, paving the way for a referendum on independence from Spain.

The proposal was carried Wednesday by 85 votes in favor, with 41 against and two abstentions.

Though symbolic, the declaration sets up a potential showdown with the central government in Madrid, which has said it will block any move toward Catalonian independence in the courts.

The declaration was backed by the region's governing Convergence and Union group and the Republican Left. It was opposed by the Catalonian Socialist Party and the Popular Party that governs Spain.

Polls show Catalonians are evenly divided over independence, but a majority opposes it if it means exiting the European Union.