Óscar Puente, a member of the Spanish Socialist Workers’ Party, had been positioned as a possible successor to Prime Minister Pedro Sánchez. He resigned from his role after two train crashes that together killed 115 people. The accidents prompted public outcry and political pressure. Before the Urda tragedy, Puente had worked closely with Sánchez during the pre‑campaign period, filling a gap left by the absence of former leader Zapatero. His departure marks a shift in the party’s succession planning.