Pro-Independence demonstrators stand by a poster of jailed former deputy Catalan president Oriol Junqueras during the Catalan National Day in Barcelona, Spain. On Thursday reports emerged that Junqueras and 17 other separatist politicians and activists are due to go on trial. File picture: Manu Fernandez/AP Photo.

Madrid - Oriol Junqueras, the former vice president of Spain's region of Catalonia, and 17 other separatist politicians and activists are due to go on trial.

After nearly one year of investigations, the Spanish Supreme Court opened criminal proceedings against the accused on charges of rebellion, disobedience and misappropriation of public funds, the court said Thursday.

No date was given for the start of the proceedings. The defendants are not likely to face a court before early 2019, according to newspaper El Pais.

Spain placed Catalonia under forced administration after the region held an independence referendum on October 1 last year and subsequently moved to secede. 

Since then, nine Catalan politicians of the former separatist government and activists have been in pretrial detention. Some were nevertheless elected to the regional parliament in fresh elections last December.

Multiple separatists, including unseated regional president Carles Puigdemont, fled into self-imposed exile.

After Catalonia's separatists reasserted themselves in the December 2017 regional elections and inaugurated its new government, Madrid ended its administration of the region.

Spain's socialist Prime Minister Pedro Sanchez, who took over from conservative predecessor Mariano Rajoy in June, has so far pursued a policy of detente and dialogue on the issue of Catalonia.