Spain's top court said on Thursday it was opening an investigation into Catalan separatist leader Carles Puigdemont on "terrorism" charges over protests linked to Catalonia's failed 2017 independence bid.
The Supreme Court said it had decided "to investigate and, where appropriate, prosecute" Puigdemont "for terrorism offences in relation to the Democratic Tsunami case".
Democratic Tsunami is a secretive Catalan group that spearheaded a string of protests after Spain jailed 13 pro-independence leaders, two years after their botched bid to separate the rich northeastern region from Spain.
Led by Puigdemont, who was Catalan regional leader at the time, the failed independence bid sparked Spain's worst political crisis in decades.
Although Puigdemont fled Spain to avoid prosecution, his fellow leaders were put on trial and on the day their sentence was handed down in October 2019, thousands of activists blocked access to Barcelona airport for several hours.
The unprecedented protest prompted the cancellation of more than 100 flights and 115 people were injured during clashes between police and protesters.
In its decision, the court referred to the crime of "street terrorism".
The aim, it said, was to "undermine law and order, to seriously breach the peace, to cause serious harm to the functioning of an international organisation or to cause a sense of terror within the population or part of it".
There was "evidence pointing to Carles Puigdemont's participation in the events under investigation", it added, citing his involvement in the group's creation "to subvert law and order and to seriously destabilise democratic institutions".
Puigdemont, who lives in self-exile in Brussels and is a member of the European Parliament, reacted drily on X.
"The same day they accuse me of receiving a 7,000-euro Rolex watch, they charge me with being a terrorist. All I need now is a secret bank account in Panama," he wrote on X.
He was referring to an article published in El Confidencial newspaper which said he had been given a Rolex watch by a company behind a string of separatist events, including the Democratic Tsunami protests.
The court's decision will complicate life for Spanish Prime Minister Pedro Sanchez, whose minority left-wing government relies on Puigdemont's hardline separatist JxCat party for parliamentary support.
Spain's government is currently in the process of drawing up an amnesty law that was demanded by Puigdemont's party in exchange for crucial parliamentary support in a November vote to reappoint Sanchez as premier.
The draft law, which was shot down by lawmakers in late January, is currently being reformulated but will essentially offer an amnesty to those wanted by the justice system over the failed independence bid, notably Puigdemont.
The move has sparked fury among Spain's right-wing opposition, which sees Puigdemont as public enemy number one.
It has also stoked opposition from within Sanchez's Socialist party.
Puigdemont is already wanted in Spain for his role in the secession bid, and the courts will need the European Parliament's permission to question him in this latest case.
