# Guillermo Montenegro Senate resignation and mayoral return > Live situation record from CLSTR: https://clstr.news/situations/guillermo-montenegro-senate-resignation-and-mayoral-return > Updated: 2026-10-05T03:06:12.000Z. Sources: 17. Developments: 2. Guillermo Montenegro, a member of the PRO party, has decided to leave his seat in the Buenos Aires Senate to resume his role as the Mayor of General Pueyrredón. Montenegro had been serving on leave from the mayoralty for ten months after being elected to the provincial Senate via the La Libertad Avanza list. His departure has triggered an internal dispute within the La Libertad Avanza party regarding his successor. While the legislative list suggests María Luján Fiego should take the position, there is growing support for Mariano Valiante. National Deputy Sebastián Pareja is reportedly favoring Valiante, using the principle of gender parity as a justification to bypass Fiego, who held the fourth spot on the electoral list. In Mar del Plata, Montenegro will replace Agustín Neme, who has served as interim mayor since December. Neme is expected to return to the local Deliberative Council. Montenegro’s return follows a period of local challenges including rising crime, high unemployment, and municipal budget deficits. ## Timeline ### 2026-10-05: Guillermo Montenegro resigns from Buenos Aires Senate Guillermo Montenegro's resignation from the Buenos Aires Senate has sparked an internal conflict within La Libertad Avanza over his replacement. 3 sources. https://clstr.news/cluster/guillermo-montenegro-resigns-from-buenos-aires-senate ### 2026-10-02: Guillermo Montenegro leaves Senate to resume General Pueyrredón mayoralty Guillermo Montenegro is leaving the Buenos Aires Senate to resume his position as Mayor of General Pueyrredón, replacing interim mayor Agustín Neme amid local security and economic concerns. 14 sources. https://clstr.news/cluster/guillermo-montenegro-returns-to-mar-del-plata-mayoralty --- Cite as: Guillermo Montenegro Senate resignation and mayoral return. CLSTR, https://clstr.news/situations/guillermo-montenegro-senate-resignation-and-mayoral-return