Spain's Attorney General Álvaro García Ortiz went on trial Monday over allegations of leaking confidential information.

The unprecedented and politically explosive case 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.

It's one of several cases 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.