Spain's Supreme Court is expected to announce on Monday its highly-anticipated verdict in the trial of 12 Catalan separatist leaders over their role in the region's 2017 banned referendum and short-lived independence declaration. 

Much is at stake, both for Spain and for its wealthiest region in this trial over a failed independence bid that attracted worldwide attention, triggered Spain's biggest political crisis in decades, and unnerved financial markets. 

Secessionist groups have called for massive but peaceful civil disobedience if the 12, of which nine have been in pre-trial detention for about two years, are not acquitted. 

It is still unclear how much support such protests may get and whether the promise of peaceful demonstrations holds. 

The court plans to convict the most prominent leaders on charges of sedition and misuse of public funds but none would be found guilty of the more severe charge of rebellion, a judicial source told Reuters on Saturday. 

A court spokesman did not comment on this and other media leaks on the verdict. 

Sentences are expected to be announced at the same time. 

The maximum prison term would be 15 years for one of the defendants, the source said. The prosecutor had sought a maximum sentence of 25 years. 

The sentences would be lower for the other eight jailed leaders, the source said. 

The remaining three who were tried – three politicians who are currently out of prison – would be found guilty of disobedience, which does not carry a prison sentence, the source said. 

The source said that it could not entirely be excluded that the court would delay the publication of its ruling to Tuesday or Wednesday. 

Separatist parties have said the only acceptable verdict for them would be the acquittal of all 12 politicians. 

The region's separatist leader Quim Torra said on Wednesday that a guilty ruling would be a "torpedo" to Catalan society. 

Catalan separatist protests have been largely peaceful but police sources have said authorities are prepared for potential violence. 

The government has said it is ready to take direct control of Catalonia – as in 2017 – if secessionist leaders break the law. 

The ruling is set to impact the run-up to Spain's fourth national election in four years, scheduled for November 10, and will also determine the separatist movement's direction. 

A poll in July showed 48.3 percent of Catalans against secession and 44 percent in favor. 

(Cover: Supporters of Catalonia's independence hold an Estelada (Catalan separatist flag) as they gesture during a protest against upcoming ruling of the Spanish Supreme Court against the independence movement's leaders, Barcelona, Spain, October 13, 2019. /Reuters Photo)