Catalans face a stark choice between pro-independence factions whose leaders have been jailed and forced into exile or parties loyal to Spanish Prime Minister Mariano Rajoy’s unpopular central government.
Recent polls show a lead for Catalonian secessionists, who used their majority in the last regional parliament to declare independence in October.
The declaration led to the Spanish government imposing direct rule over Catalonia after they decreed the secession referendum illegal.
Despite a crackdown by the federal government, separatist parties remain defiant.
Acting head of the Catalan Republican Left (ERC) party, Marta Rovira said she was to learn lessons from ex-Catalan leader Carles Puigdemont.
She said: “The first thing we do if we come to power is to call the Spanish Government for dialogue and negotiation. That is clear.
“We don’t know how the Government will respond, but we ask it to respect the result of the election.”
Ms Rovira told politics news site Politico.co.uk she would push for “all those reforms and policies that we are allowed to that will bring Catalonia forward without asking for the Spanish Government’s permission”.
She added: “The problem is that the constitution could not have envisaged the problems we would have in 2017, about energy poverty or about gender equality, those competencies weren’t distributed.
“So we’re going to launch a negotiation with employers, and we’re going to make an agreement on gender equality.
“Who’s going to try and impede this? The Spanish Government. We’re going to try and build a republic.”
A recent poll shows ERC is expected to get 23 per cent of the vote, the largest single share of Thursday’s vote.