King Felipe VI charged Prime Minister Pedro Sanchez this week with forming a new government, for which he needs crucial support from a hardline Catalan separatist party.

In exchange, the party has demanded an amnesty for those facing legal action over Catalonia’s failed 2017 independence bid which triggered Spain’s worst political crisis in decades.

The proposal has enraged the right which says amnesty cannot be used as a bargaining chip for Sanchez to remain in power.

Huge crowds waving Spanish and Catalan flags flooded Barcelona city centre for the rally called by Societat Civil Catalana (SCC) which is opposed to the northeastern region breaking away from Spain.

Spain has been mired in political uncertainty since an inconclusive July election that was won by the right-wing Popular Party but without enough support to form a government, with leader Alberto Nunez Feijoo failing a key September vote to become premier.

Now it’s Sanchez’s turn and his Socialists and their hard-left Sumar allies support the idea of granting the amnesty demanded by JxCat, whose leader Carles Puigdemont led the 2017 secession bid then fled Spain to avoid prosecution and would benefit from the move.

The idea is anathema to the right for whom Puigdemont is public enemy number one and also a red line for some within Sanchez’s Socialist party.

“No amnesty!” and “Send Puigdemont to prison!” shouted the demonstrators, who numbered more than 50,000, Barcelona police said. Organisers gave a figure of 300,000.

“This is not an amnesty that seeks reconciliation, it is exclusively aimed at getting into the prime minister’s office,” said Feijoo, whose bid to become prime minister with the support of the far-right Vox left him isolated within the parliament.

“It’s unacceptable that politicians should break the law, some to reach the prime minister’s office… others to settle their debt with the law,” he said, as Vox leader Santiago Abascal, who was also there, blasted it as “an assault on the Constitution”.

Sumar to present amnesty document

Sanchez has shown himself to be a tenacious political survivor with a knack for striking deals with rival parties and is confident he will be returned to power, pledging “generosity” in talks with the separatists while admitting they would be “complicated”.

He began formal talks with Sumar about renewing his mandate this week, with the hard left party’s leader Yolanda Diaz, who is also acting labour minister, due to lay out a legal document on the amnesty proposal in Barcelona on Tuesday.

“We are aware of Sumar’s proposal about the amnesty as well as those of other parties which is good because it’s a way of trying to resolve the judicial implications” of the 2017 independence bid, he said during an EU summit in Granada on Friday.

The document has already been sent to JxCat, which thanked Sumar for its “willingness to reach an agreement” and pledged to look at it in detail. The party’s more moderate separatist rival ERC — on whom Sanchez is also counting for support — also received a copy.

Sanchez, who has sought to calm separatist tensions since coming to office five years ago, in 2021 pardoned Catalan separatist leaders who were serving long prison terms over the secession bid.

Sanchez needs to secure support from at least 176 lawmakers within the 350-seat parliament to win a key vote that must take place before November 27.

If he fails, Spain will automatically be forced to hold new elections, most likely in mid-January.

At Sunday’s rally, 53-year-old lecturer Araceli Rodriguez told AFP she was “absolutely against” an amnesty because it would be akin to whitewashing the 2017 crisis.

“What you cannot do is to sell out Spanish democracy on the strength of only seven votes,” said Rodriguez, referring to the votes of JxCat’s seven lawmakers.

“Approving an amnesty is selling out Spanish democracy for the partisan interests of a party that didn’t even win the election.”