A video has emerged from the Catalan town of Artesa de Lleida of voters outside a polling station applauding the arrival of local Catalan police.
The Mossos d' Esquadra are the police force of Catalonia which largely replaces the Policia Nacional and Guardia Civil of other regions of Spain.
They operate under the authority of the Generalitat de Catalunya rather than the interior ministry in Madrid.
Tens of thousands of Catalans are expected to vote in the ballot, which will have no legal status as it has been blocked by Spain’s constitutional court.
Madrid has sent thousands of police to the region to stop it taking place