Zapatero, who led Spain from 2004 to 2011, began the first of two days of hearings at the Audiencia Nacional court over allegations of influence peddling linked to the 2021 state bailout of airline Plus Ultra.

The investigation centers on a 53 million euro ($61.5 million) rescue package granted to the carrier after the COVID-19 pandemic severely disrupted global air travel. Investigating magistrate Jose Luis Calama alleges that Zapatero headed a “stable and hierarchical” network that used opaque financial channels to conceal money flows and secure illicit payments connected to the bailout process.

Zapatero has categorically denied any wrongdoing. Prime Minister Sanchez has publicly expressed his “full support” for the former leader, widely regarded as his political mentor within Spain’s Socialist movement.

The case broadened after police searches of Zapatero’s office reportedly uncovered jewelry and luxury watches valued at approximately 1.3 million euros. The findings prompted investigators to examine potential tax fraud and smuggling offenses in addition to the original influence-peddling allegations.

Individuals close to Zapatero have said the valuables originated from a family inheritance and reject any suggestion of criminal conduct.

The proceedings come at a particularly sensitive moment for Sanchez, whose administration is already confronting multiple corruption investigations involving members of his inner political circle and family.

A separate inquiry into his wife, Begona Gomez, over alleged influence peddling has weighed heavily on the government for two years, with a judicial decision on whether to proceed to trial expected in the coming days.

Legal proceedings are also underway involving former Transport Minister and longtime Sanchez ally Jose Luis Abalos, while another case concerns the prime minister’s brother, David Sanchez.

Additional pressure emerged following reports of a police investigation into a former Socialist activist suspected of orchestrating efforts to obstruct corruption inquiries involving figures linked to the governing party.

The accumulation of legal controversies has weakened the Socialists politically. Since late 2025, the party has suffered four regional election defeats, fueling speculation about the impact the scandals could have on Spain’s next national election.

Sanchez rose to power in 2018 after pledging to restore integrity to Spanish politics following a major corruption scandal that resulted in the conviction of the conservative Popular Party (PP). Opposition parties now argue that the government faces its own credibility crisis and have called for Sanchez’s resignation and an early general election.

The prime minister has rejected those demands and insists he will remain in office until the end of his term in 2027. He has continued to highlight his government’s economic and social policy achievements while avoiding detailed public comment on the ongoing investigations.

Political scientist Astrid Barrio of the University of Valencia said the case carries significance beyond its legal implications because of Zapatero’s symbolic influence within the ruling Socialist Party.

“What is at stake is the reputation of someone who has become the moral beacon of Pedro Sanchez and the current Socialist Party,” Barrio said.

She added that two developments could pose the greatest threat to Sanchez’s political survival: the possibility of the prime minister himself becoming the subject of a formal investigation or prosecutors pursuing allegations of illegal party financing against the Socialists.

Protesters carrying Spanish flags and banners reading “Enough!” gathered in the capital following a call by Sociedad Civil Española, a coalition of more than 150 civic associations. The demonstration was backed by the conservative Alberto Núñez Feijóo-led Popular Party and the far-right Santiago Abascal party.

Organizers estimated attendance at around 80,000 people, while the central government’s representative in the Madrid region put the turnout at roughly half that figure. The march concluded near Plaza Moncloa, close to the prime minister’s official residence.

Speaking before the rally, Vox leader Abascal accused the government of being engulfed in corruption scandals, arguing that allegations involving individuals close to Sanchez had eroded public confidence in the administration.

The demonstration comes amid mounting scrutiny of figures linked to the prime minister. Sanchez’s brother, David Sanchez, is due to stand trial on influence-peddling charges, while his wife, Begona Gomez, remains under investigation in a separate corruption inquiry. Sanchez has repeatedly rejected the allegations and described the cases as politically motivated.

Pressure on the government has also increased following legal proceedings involving former transport minister Jose Luis Abalos, a longtime Sanchez ally whose corruption trial concluded earlier this month and is awaiting a verdict.

Adding to the political challenges facing the government, a Spanish court this week placed former prime minister Jose Luis Rodriguez Zapatero under formal investigation for alleged influence peddling and other offenses. Zapatero has been regarded as a close ally of Sanchez within Spain’s Socialist movement.

Sanchez, who came to power in 2018 after a no-confidence vote removed a conservative government plagued by corruption scandals, has insisted he will remain in office despite growing opposition demands for early elections.

The rally underscored the increasingly polarized political climate in Spain, where corruption allegations have become a central battleground ahead of future electoral contests.