Political parties opposed to a push by Catalonia's government to break away from Spain gathered in the powerful north eastern region's capital to call for an end to secessionism.
Thousands of protesters filled Barcelona's central Sant Jaume square Sunday under the banner of The Independence Process Robs Us Of Our Identity.
Rafael Arenas, president of the Catalan Civil Society organisation, addressed the gathering saying pro-independence politicians "are trying to rob us of Spain" and were "promising heaven and earth" to gain support for their secessionist cause.
Mr Arenas said it was unwise "to add a Spanish national implosion" to Europe's current difficulties.
On January 10, Catalonia's parliament voted in new leader Carles Puigdemont who says he is determined to forge ahead with a drive to secede from Spain by 2017.