The 2015 elections were the first to use an electronic voting system in the city, similar to the one used in Salta Province. In these elections held on 5 July 2015, Macri stepped down as mayor and pursue his presidential bid and Horacio Rodríguez Larreta took his place as the mayoral candidate for PRO. In the first round of voting, FPV's Mariano Recalde obtained 21.78% of the vote, while Martín Lousteau of the ECO party obtained 25.59% and Larreta obtained 45.55%, meaning that the elections went to a second round since PRO was unable to secure the majority required for victory. The second round was held on 19 July 2015 and Larreta obtained 51.6% of the vote, followed closely by Lousteau with 48.4%, thus, PRO won the elections for a third term with Larreta as mayor and Diego Santilli as deputy. In these elections, PRO was stronger in wealthier northern Buenos Aires, while ECO was stronger in the southern, poorer neighborhoods of the city.