Cerdán will defend himself by delving into Koldo's police past.

Santos Cerdán will seek to distance himself from Koldo García and José Luis Ábalos and will attempt to link their involvement in the alleged corruption scheme that is shaking Pedro Sánchez's government to an operation orchestrated from within the Civil Guard through the former.

Cerdán, in prison since June 30, maintains his innocence. Although the voice is his, it is not recognizable in the recordings that have emerged, meaning he claims to have never held conversations with García about sharing commissions for public works, according to sources close to the former PSOE organization secretary's defense team. Initially, this is because Cerdán lacked room to maneuver in the Ministry of Transport from his position in the PSOE. These same sources emphasize that the politician insists that investigators will never find hidden bank accounts or properties, the result of alleged bribes, simply because they do not exist. "There has been no increase in his assets, something that is incompatible with the prosecution's thesis," they explain.

Cerdán's defense will try to investigate the relationship between García and the Civil Guard, which decorated him in 2018.

For the time being, the burden of Cerdán's indictment focuses on the recordings made by Koldo García. His defense will attempt to delve deeper into the shadows surrounding the figure and those of the recordings themselves. Before becoming Ábalos's advisor at the Ministry of Transport, García may have held a role as an informant for the Civil Guard. His first jobs during his years in Pamplona were as a security guard and nightclub bouncer. In 2018, he was awarded the Order of Merit of the Civil Guard, in the category of Cross with White Distinction, which recognizes "actions or conduct of extraordinary significance, which contribute to the prestige of the Corps and the interest of the Nation," and can be awarded to officers of the corps or civilians. He received the medal on May 3, 2018, less than a month before Pedro Sánchez's motion of censure, which brought down Mariano Rajoy's government, was successful.

The first recording made by García that has been made public is from less than a year later: April 9, 2019. The medal award file detailing these merits is confidential. Therefore, Cerdán's defense will attempt to investigate the relationship between García and the Civil Guard, whose Central Operational Unit (UCO) is responsible for the investigation.

García was also pardoned by the PP government in 1996 for a beating while he was a landfill security guard.

The second pillar of Cerdán's defense will be to question the integrity and origin of the recordings. He has commissioned an expert opinion to determine whether they have been edited, what devices they were made with and on what dates, where they were stored, and what they all contain. The analysis will take several weeks to complete. Cerdán will request access to all the recordings, which appear to number in the thousands and have required a tremendous amount of classification and documentation work. Sources involved in the case estimate that the recordings have a computing capacity of at least two terabytes, implying extensive training and knowledge.

The defense strategy does not contemplate a plea deal with the prosecution that would soften a possible sentence, nor does it contemplate collaboration or coordination with the other two main defendants in the alleged plot, Ábalos and García. Cerdán is currently under investigation in the case being conducted by the Supreme Court (SC), while Ábalos is still a member of Congress, but currently without affiliation. Cerdán resigned his seat and lacks immunity, but he is not a defendant in the original case, which is being conducted for most of those involved by Central Court No. 2 of the National Court.

In the appeal filed by Cerdán's lawyers to request his release, they argue that there is no connection between him and the plot being investigated by the Supreme Court, which referred to public works concessions during Ábalos's time as Minister of Transport, between 2018 and 2021. Two of the projects under investigation (the Mina Muga concession, between Aragón and Navarra, and the renovation of the Navarra Arena pavilion), in which the company Servinabar was involved, in which Cerdán may have had a percentage, were carried out during a period in which he "did not hold any position in the public administration" and his party, the PSOE, was in the opposition in both Navarra and Madrid.