Catalans go to the polls Dec. 21 to elect representatives to their 135-seat regional parliament in a close-run contest dominated by the region's debate on secession from Spain.
Spanish Prime Minister Mariano Rajoy called for the snap election after dismissing the Catalan government and imposing direct rule on the region following a unilateral declaration of independence on Oct. 27.
Support for parties demanding independence has been neck-and-neck with parties calling for the region to remain in Spain, a poll of polls in daily newspaper El País showed Dec. 19.
A fragmented outcome could mean a challenging round of negotiations to form another coalition government. If deadlock persists, then Madrid is expected to call a second round of elections.
Results are not expected until midnight local time, local media reported.
The political uncertainty resulting from the region's secessionist drive has already prompted the Spanish central bank to trim its growth forecast to 2.4% for 2018 and 2.1% for 2019.