Mr. Sánchez declared last week that he was calling off all of his official commitments following the opening of a preliminary investigation into his wife’s alleged corruption by a judge.
He referred to the claims as a right-wing media-led campaign of harassment.
Since 2018, Mr. Sánchez has held this position.
His decision last week to step away from his duties and think about whether it was still worthwhile to be prime minister surprised even members of his own Socialist Party (PSOE).
Begoña Gómez, the spouse of Mr. Sánchez, was accused by Manos Limpias (Clean Hands), an organization headed by a guy connected to Miguel Bernad.