After a drama-packed autumn, Catalonia is preparing for a climactic regional election on December 21st. Spanish Prime Minister Mariano Rajoy hopes the vote will strip pro-independence parties of their parliamentary majority, while ousted Catalan President Carles Puigdemont and his allies hope that their movements earn over 50% of the popular vote—an effective endorsement of Catalan independence. For eurosceptics, a lot is at stake in this election: either Madrid successfully snuffs out the independence movement, or Catalonia pursues its current course out of Spain and the EU.

Broadly speaking, Catalonia’s political parties belong to two camps: those for and those against Catalonia’s secession from Spain. However, there remain important divisions within each group.

Pro-independence parties

In November, Puigdemont’s Catalan European Democratic Party merged with independents to form Together for Catalonia (JunstxCat). This movement supports the October 27th declaration of independence, and is currently polling in third or fourth position.

Perhaps contributing to JunstxCat’s low polling compared to previous elections is the rise of the more aggressively pro-independence Republican Left of Catalonia (ERC). Once Puigdemont’s junior coalition partner, the ERC is now leading in most polls. Its former leader, Oriol Junqueras, decided to remain in Catalonia to be imprisoned, while Puigdemont fled to Belgium. An ERC-led government is likely to double down on the independence process, rather than playing for time or waiting to obtain a better bargaining position vis-à-vis Madrid.

Other pro-independence parties include the staunchly socialist Popular Unity Candidacy (CUP), and, to a lesser extent, the Catalonia in Common (CatComú) party, which is pro-sovereignty and pro-referendum, but not explicitly in favour of a Catalan nation-state. CatComú may well play the role of kingmaker in any future parliamentary votes on secession.

Together, these parties consistently represent a majority of opinion across polls. Depending on whether Catalans follow through in the ballot box, there are strong odds the parliament they elect will broadly support independence, or at least reject Madrid’s attempts to quell dissent.

Pro-union parties

Between them, Rajoy’s conservative People’s Party (PP) and the social democratic Socialists’ Party of Catalonia (PSC) barely make up a fifth of recent polling. Both are against Catalan independence, and support the central government’s efforts in this regard. However, the most prominent anti-independence party is the liberal Citizens party, which has been polling at approximately 20% or above in recent weeks.

Together, pro-union parties represent just over 40% of polling, giving a slight edge to pro-independence parties. However, with CatComú positioning itself as neither pro-Madrid (which it believes represents the austerity policies of the past decade), nor explicitly pro-independence, there is a strong chance that neither side of the Catalan debate obtains a majority of votes this election.

Ultimately, only Catalans can decide what will happen next, by either sending a strong signal in favour of following through on October’s declaration, or by sealing the region’s fate within Spain. Either way, the repercussions of their choice will reverberate far beyond their borders.