- While separatists control the regional government in Catalonia, they have been unable to agree on how to push ahead for independence for the region that accounts for a fifth of Spain's economic output.
- Former Catalan vice-president Oriol Junqueras and eight others face the most serious charge of rebellion. Public prosecutors have asked that he spend 25 years behind bars.
- Senior separatist leaders are in jail awaiting their verdicts or scattered abroad, such as former Catalan president Carles Puigdemont who fled to Belgium shortly after his government made the failed independence declaration.
Divided after their failed 2017 secession bid, Catalonia's separatists will hold a rally in Barcelona on Wednesday that will test their strength before a Spanish court in October serves verdicts against the leaders of the independence push.
Since 2012, separatists have held massive rallies on September 11, Catalonia's "national day", which marks the fall of Barcelona to Spain in 1714. Organisers say a million people took part in past "Diada" rallies.
This year's demonstration will get underway at 5.15pm (1514 GMT) -- a nod to the year -- on Barcelona's central Plaza Espana.
The rally comes just a few weeks before Spain's Supreme Court is due to deliver verdicts in the high-profile trial of 12 separatist leaders charged over their role in Catalonia's separatist bid, which plunged the country into its worst political crisis in decades.
Former Catalan vice-president Oriol Junqueras and eight others face the most serious charge of rebellion. Public prosecutors have asked that he spend 25 years behind bars.
Catalan separatist leaders have tried for months to prepare a united response to the looming verdicts but they remain increasingly split over strategy.
"On the eve of these verdicts, it is important that we are seen as strong and massively mobilised," Elisenda Paluzie, the president of powerful grassroots pro-independence group ANC which organises the protest, told AFP.
The mood in the separatist camp is very different from two years ago when Catalonia's regional government pushed ahead with a banned independence referendum in Catalonia on October 1, 2017 that was marred by police violence, and then made a short-lived declaration of independence.
Senior separatist leaders are in jail awaiting their verdicts or scattered abroad, such as former Catalan president Carles Puigdemont who fled to Belgium shortly after his government made the failed independence declaration.
While separatists control the regional government in Catalonia, which is home to around 7.5 million people, they have been unable to agree on how to push ahead for independence for the region that accounts for a fifth of Spain's economic output.
"It is essential to have a united strategy that allows us to achieve independence. The first step is filling the streets on September 11," the ANC said in a statement.
Demonstrators will form the shape of a giant star which the ANC says will symbolise a state "as well as the joint effort of the Catalan people to defend their right of self-determination".
But unlike in 2017, Catalonia's two main separatist parties which govern the region are at odds over the path ahead.
Puigdemont's Together for Catalonia party has called for "confrontation" with Madrid if the Supreme Court hands guilty verdicts against the 12 separatist leaders.
But Junqueras' leftist party ERC has called for dialogue with Spain's central government, which is less hostile to the separatists since Prime Minister Pedro Sanchez's Socialists came to power in June 2018.
Catalan vice president Pere Aragones of the ERC said Tuesday that the "harsher the sentence... the greater the need there will be to settle this issue politically".
Against this backdrop of division, there are fears that turnout at this year's rally will drop.
Quim Alvarado, a 47-year-old historian from the town of Figueras, said he saw no reason to attend.
"We are at an impasse that I fear will be eternal. I am certain that my generation and the next will not see independence," he said.
Radical separatists meanwhile have called for an alternative rally outside of Catalonia's regional parliament, which they want to occupy.