MADRID - Spain's Supreme Court on Monday upheld arrest warrants for Catalonia's former leader and others charged with embezzlement over the region's failed secession bid, as it ruled that a recent amnesty law does not apply to them.

The decision, which can be appealed, could scupper the fragile Socialist-led coalition ruling Spain and have personal implications for ex-Catalan leader Carles Puigdemont, who is living in France in self-imposed exile.

An amnesty law passed on May 30 was meant to pardon those involved in the 2017 attempt to declare Catalonia's independence from Madrid in exchange for the critical support of separatist parties for Prime Minister Pedro Sanchez's new term after an inconclusive general election.

Investigating judge Pablo Llarena said in his writ he would continue to seek the arrest of Puigdemont and his former deputies Antonio Comin and Lluis Puig, who were in charge of Catalonia's health and culture departments, respectively.

A withdrawal of support from Puigdemont's Junts party for bills such as the 2025 budget could leave Sanchez unable to govern and trigger new elections.

Politicians and activists involved in the independence drive faced charges including public disorder, disobedience and embezzlement.

But two exceptions were carved out for embezzlement, so the amnesty does not apply to those who committed the felony with the intention of personally enriching themselves or if it affected the European Union's financial interests.

Llarena argued that the alleged conduct of Puigdemont, Comin and Puig "fully fits within the two exceptions contemplated in the law".

Llarena said they obtained personal gain by charging the expenses of holding an independence referendum deemed illegal by the Spanish judiciary to the regional treasury, a move he described as not being in the public interest.

All three say the referendum was not illegal and so the charges linked to it have no basis.

The referendum had also affected the European Union's financial interests, Llarena said, as Catalonia's secession would have impacted Spain's tax collection and gross national income.

The ruling is a blow for Puigdemont, who had appeared optimistic that the amnesty would fully clear all the accusations he faced in Spain, allowing him to return without the fear of arrest.

Junts did not immediately respond to a request for comment.

  - Reuters