Spain`s Attorney General Álvaro García Ortiz went on trial Monday over allegations of leaking confidential information in an unprecedented and politically explosive case that looms large over Prime Minister Pedro Sanchez` s left-wing government.

It`s the first time in Spain`s modern history that a top prosecutor faces a criminal trial. The case is one of of several that have implicated people close to Sánchez.

García Ortiz is accused of having leaked an email to journalists from a lawyer who was representing the partner of Madrid`s influential regional leader Isabel Díaz Ayuso, one of Spain`s main opposition leaders. Díaz Ayuso`s partner, a businessman named Alberto González Amador, was under investigation for alleged tax fraud. García Ortiz has denied the charges and has received public support from Sánchez on more than one occasion.

The case against García Ortiz is at the heart of tensions between Spain`s left-wing national government and Madrid`s conservative regional government. The trial is expected to conclude next week.

García Ortiz was appointed attorney general in 2022.

Two former high-ranking officials in Sánchez`s Socialist Party are facing separate corruption investigations, as well as the prime minister`s wife and brother. While Sánchez himself has not been named in any of the cases, they have at times threatened to bring down his government.

Sánchez has said that some judges in the country were acting on political motives when asked about the investigations into his wife`s business dealings.