The separatist parties that lead the regional government are battling for control of the local parliament with the Socialists of Prime Minister Pedro Sanchez, who has made it a priority to resolve a crisis that led to a short-lived declaration of independence in 2017 after a banned referendum.
A poor performance by the hardline separatist party that heads the ruling coalition would be likely to calm calls for another referendum or further moves to full independence.
However, the courts are still deciding whether to allow the February 14th poll.
The Catalan government wanted the vote pushed back to May 30 because of increasing virus infections but judges suspended the date change after smaller parties objected to the delay.
The court now has until February 8th to give its final ruling.
Catalan separatists have governed the region of around 7.8 million people since 2015 but recent polls suggest the Socialists – who are fielding former health minister Salvador Illa as their most high-profile candidate – could come in first place.
Taking office may not be so easy though as separatist parties are likely to once again be able to cobble a governing majority if they join forces.
The vote will decide the make up of Catalonia's 135-strong regional parliament, which decides health and education policy in the region.
A victory for the Socialists in Catalonia would strengthen Sanchez's hand at the national level against a conservative opposition that is fiercely critical of his handling of the separatists, said Oriol Bartomeus, a political scientist at the Autonomous University of Barcelona.
The election could also pave the way for a resolution of Catalonia's separatist crisis if the hardline Together for Catalonia party that leads the outgoing coalition loses ground to the more moderate Esquerra Republicana de Catalunya (ERC), he added.
“The possibility of resolving the (Catalan) conflict depends on the outcome of the internal battle in the separatist camp,” Bartomeus told AFP.
Sanchez has worked with the ERC and is mulling pardoning nine Catalan separatist leaders serving jail terms over the failed independence bid — including ERC head Oriol Junqueras.
The elections are highly unpredictable because it is not clear how turnout will be affected by the pandemic and how this will impact parties, said Ana Sofia Cardenal, a political scientist at the Open University of Catalonia.
In locked-down Portugal, a record 60.6 percent abstained in a presidential election on Sunday.
Catalan authorities have made it easier to vote by mail while the final hour of voting will be reserved for people who have tested positive for the virus or are in quarantine.
By AFP's Daniel Bosque