The 2015 Madrid City Council election, also the 2015 Madrid municipal election, was held on Sunday, 24 May 2015, to elect the 10th City Council of the municipality of Madrid. All 57 seats in the City Council were up for election. The election was held simultaneously with regional elections in thirteen autonomous communities and local elections all throughout Spain. Leading the People's Party (PP) local list was Esperanza Aguirre, former president of the Community of Madrid (2003–2012), president of the Senate of Spain (1999–2002) and minister of Education and Culture (1996–1999), as well as the leader of the regional PP branch since 2004. Mayor Ana Botella, who succeeded Alberto Ruiz-Gallardón early into his term in December 2011, had declined re-election in September 2014. The election was an unexpectedly close race between Aguirre's PP and former judge Manuela Carmena's Podemos-supported Ahora Madrid () platform. The collapse in the PP vote and the loss of its absolute majority allowed Carmena to gain power through an alliance with the Spanish Socialist Workers' Party (PSOE), resulting in the first left-wing government in the city since 1989. The PSOE suffered heavily from tactical voting to Ahora Madrid after it became apparent throughout the campaign that the left-of-centre vote was coalescing around Carmena's coalition. The newcomer liberal Citizens () party also entered the City Council for the first time, collecting votes disenchanted with the PP and replacing Union, Progress and Democracy (UPyD) as the main centrist local force. United Left (IU) fell below the 5% threshold and failed to gain any representation for the first time in history. Electoral system The City Council of Madrid () was the top-tier administrative and governing body of the municipality of Madrid, composed of the mayor, the government council and the elected plenary assembly. Elections to the local councils in Spain were fixed for the fourth Sunday of May every four years. Voting for the local assembly was on the basis of universal suffrage, which comprised all nationals over 18 years of age, registered and residing in the municipality of Madrid and in full enjoyment of their political rights, as well as resident non-national European citizens and those whose country of origin allowed Spanish nationals to vote in their own elections by virtue of a treaty. Local councillors were elected using the D'Hondt method and a closed list proportional representation, with an electoral threshold of five percent of valid votes—which