A judge in Spain has issued a European arrest warrant for former Catalan president Carles Puigdemont and his cabinet colleagues who fled to Belgium after facing charges including sedition and rebellion.

The warrant, which adds two further indictments of perjury and willful disobedience of the law, is the first step in attempts to extradite the Catalan leadership to face trial which carries a possible sentence of 30 years on conviction.

The latest escalation in the crisis came as Barcelona’s city council published a declaration demanding the immediate release of eight Catalonian ministers being held by the Spanish authorities after they attended a court hearing in Madrid. But the regional politicians are being increasingly viewed by many independence supporters as impotent in the current confrontation, with Madrid seemingly holding the whip hand.

There appears to be little prospect of the detained men being released and there were reports, unconfirmed, that a European arrest warrant has already been issued for Mr Puigdemont, the region’s President and his colleagues who had fled to Belgium after facing charges including sedition and rebellion. At the same time a court panel today rejected an appeal for the release of two activists who were jailed last month after the declaration of independence by the Catalan government following a referendum.

With the government of Mariano Rajoy taking a tough and uncompromising stance, a growing number of separatist activists believe the answer lies in mobilising street power. Thousands came out to protest on Thursday night in Barcelona and other Catalan towns after the jailing of the leaders and The Committee for the Defence of the Republic – a grassroots group – has called for demonstrations to continue in the coming days.

The crowds had chanted “ Freedom for Political Prisoners” and “ Puigdemont Our President” and sang the Catalan national anthem, “ Strike with your sickle, defenders of the land” as they converged in central Barcelona in front of two iconic public buildings which highlight the fractured nature of governance here at the moment . The Generalitat, the headquarters of the regional executive, has been taken over by Madrid while the Catalans hang on to the Casa de la Ciutat, the City Hall.

Catalan pro-unity demonstration – in pictures Show all 6 1 /6 Catalan pro-unity demonstration – in pictures Catalan pro-unity demonstration – in pictures Pro-unity supporters take part in a demonstration in central Barcelona. Hundreds of thousands of Catalans took to the streets of Barcelona on Sunday to call for their region to remain part of Spain, two days after regional lawmakers exacerbated a political crisis by voting for the wealthy region to secede Reuters/Jon Nazca Catalan pro-unity demonstration – in pictures A woman with the Senera and Spanish flags painted on her face shouts slogans as she takes part in a rally against Catalonia's declaration of independence, in Barcelona AP Photo/Gonzalo Arroyo Catalan pro-unity demonstration – in pictures Thousands of pro-unity protesters gather in Barcelona, two days after the Catalan parliament voted to split from Spain Jeff J Mitchell/Gett Catalan pro-unity demonstration – in pictures People support a pro-unity demonstration from their balconies in central Barcelona Reuters/Rafael Marchante Catalan pro-unity demonstration – in pictures Pro-unity supporters take part in a demonstration in central Barcelona Reuters/Yves Herman Catalan pro-unity demonstration – in pictures Protesters wave Spanish flags and carry banners during a pro-unity demonstration on in Barcelona Jack Taylor/Getty

There were calls from the marchers for the Spanish flag on the Generalitat to be torn down : but no attempts were made to do so. The heavy presence of Guardia Civil in large numbers sent in from other parts of Spain was a very visible deterrence but those taking part repeatedly stressed that they wanted to avoid violence and continue protesting while also channelling their energy into fighting the regional election called in December by Madrid.

Mateu Porra, who had arrived from an outlying village to take part in the rallies, wanted to caution : “The Spanish will use any trouble as an excuse to take hard measures, arrest people and send in more of their police. We must not give them that opportunity. At the same time the size of the crowds we get will show that we are not going to give up.”

Ariadna Olivas, an activist organiser, added “It is important to keep up the pressure. But we must also plan for the election. A lot of people had wanted to boycott it because it is imposed by the Spanish. But that is no longer an option, we must vote if we want independence. The people will have to do a lot of organising with so many of the leaders in prison. We don’t know what will happen to President Puigdemont even.”

Speaking to Belgian TV Mr Puigdemont said: “I will not flee from justice. I will go towards justice, but real justice. I’ve told my lawyers to tell the Belgian justice system that I’m completely available to cooperate. It’s obvious it’s politicised. The guarantees are not there for a fair, independent trial.” He called on Catalans to continue their protests “ without violence, peacefully and with respect for everybody’s opinions”.

Mr Puigdeont’s lawyer in Brussels, Paul Bekaert, believes that the warrant for the arrest of his client and four others have already been issued, although there has been no corroboration of that by the Spanish authorities.

Mr Bekaert repeated that Mr Puigdemont would not be voluntarily going back to Spain for the time being. “The atmosphere is not good to give testimony at the moment, it is better to step back”, he said. “ They can have him arrested and handcuffed. Bu the investigating judge does not have to arrest him. He can also leave Mr Puigdemont at liberty under certain conditions. I will try to go down these alternative routes.”

Judge Carmen Lamela of the National Audience Court, in charge of issuing the warrant, will need to send papers to prosecuting authorities in Belgium who, if they decide the documents are correct, will have 15 days to arrest Mr Puidgemont and the four others. Mr Baekart said that his client will appeal any decision to comply with the Spanish request. This will take a minimum of 15 days more and further legal processes may extend the timeframe past the election due to be held 21st December.