STREETS in Barcelona were a sea of yellow yesterday as hundreds of thousands of protesters marched through the Catalan capital in defence of political prisoners and exiled politicians, including sacked president Carles Puigdemont and Professor Clara Ponsati, from St Andrews University, who served as his education minister.

The demonstration – under the banner of Space, Democracy and Coexistence – was the biggest seen during Spain’s worst political crisis in decades.

It took place six months after the imprisonment – without trial – of Jordi Sànchez, former president of the Catalan National Assembly (ANC), now a pro-independence MP, and president of Òmnium Cultural, Jordi Cuixart.

Saltires flew alongside the Catalan Estelada as the huge, but peaceful crowd, made its way through the city in a massive show of support for independence, political freedom and the ending of Article 155 under which the Madrid government imposed direct rule on Catalonia following its declaration of independence in October.

In a message from prison in Soto del Real, Cuixart tweeted: “United in the face of injustice and authoritarianism. Hope in the incorruptible dignity of the Catalan society democracy and freedom. Hope in a future without disclaimers. Unity, dignity and courage. Long Live Catalonia!”

In a separate message, Sànchez wrote: “Thank you for always being there! Light in the eye and the arm! Do not forget the lesson of determination of the 1st of October, its democratic values and not violent. Keep the commitment to serve the country and my fellow citizens. We are not afraid, we have the right to be free.”

Puigdemont tweeted from Germany: “Once again a great, peaceful and democratic demonstration. Catalonia asks for freedom. We are European citizens who simply want to live in peace and without fear.”

Speaker of the Catalan parliament, Roger Torrent, was at the head of the procession, along with Ada Colau, mayor of Barcelona, other politicians and the families of the prisoners and the exiled.

Police put the number of demonstrators at 350,000 while the organisers claimed it was 750,000.

Camil Ros, general secretary of the UGT union in Catalonia, one of the event’s organisers, said the protest was about dialogue.

“The main organisations of the state demand dialogue,” he said. “Most people in Catalonia are against jail and 155. We are here to build bridges.

Javier Pachecho, from the CCOO union, said they had a part to play in the battle against repression.

“We have to build the widest possible spaces that represent the plurality and diversity of Catalonia, and our organisations have the capacity to express this reality,” he said.

A manifesto document signed by the organisers expressed concern over “the violation of fundamental rights and democratic freedoms and the social polarisation produced in the current situation”.

The heavily politicised Spanish judiciary has blocked the inauguration of Puigdemont as president, as well as Sanchez, and the document called for a new government to be set up that can fully exercise its powers and normalise its various institutions.

It added: “Given these facts, we do not rule out any peaceful way of mobilising and responding to the country.”