, the longest pedestrianized street (2,8 km) On 7 May 2014, Ada Colau announced her resignation as spokesperson of the PAH. In June 2014 she founded
Barcelona en Comú (formerly known as Guanyem Barcelona), a citizen platform that stood in the May 2015 Barcelona municipal elections. Barcelona en Comú won a plurality in the elections (11 of 41 city council seats) and on 13 June 2015 she was sworn in as mayor with the favourable vote of an absolute majority of councillors. She headed again the Barcelona en Comú list vis-à-vis the
26 May 2019 Barcelona municipal election. The list came up second, close to the ERC list headed by
Ernest Maragall, with the same number of municipal councillors (10) as the latter. On 15 June 2019, during the inaugural session of the new municipal council, Colau commanded a qualified majority of the plenary for the investiture vote (21 out of 41 municipal councillors; presumably with the endorsement of the 10 municipal councillors of Barcelona en Comú, along with the 8 municipal councillors of the PSC and 3 out 6 individual councillors of the Barcelona pel Canvi–Ciutadans list:
Manuel Valls,
Celestino Corbacho and Eva Parera), thus renewing her mandate as Mayor of Barcelona. However, her party lost the majority on the
28 May 2023 Barcelona municipal election. In 2018, after a legal battle, she obtained the lifting of the Constitutional Court's veto on the expropriation of empty dwellings. More than 2,000 bank-owned homes that have been unoccupied for several years could be converted into social housing. During her period as mayor of Barcelona, Colau has maintained a political stance against activities that are susceptible of contributing to
greenhouse gas emissions and
air pollution. She has repeatedly opposed the expansion of
El Prat airport and the use of private cars in the city, and has pushed regional authorities to restrict the number of cruise ships arrivals in Barcelona. In 2020 she declared a "climate emergency", advocating limiting the consumption of meat at schools and forbidding councillors from using the Barcelona-Madrid air shuttle. Colau also called for a reduction of air traffic during the
C40 Cities 2019 summit, arguing that aeroplanes generate greenhouse gas emissions that are "very dangerous for the planet". Although Spanish municipalities have little power in the area of
public health, which is usually the responsibility of the regions, Ada Colau's administration has made the mental health of residents, especially the youngest, one of its priorities. As soon as she came to power, she set up the 2016–2022 mental health plan, which included 170 initiatives and led, in particular, to the creation of various reception structures, the Konsulta'm. Some initiatives, such as the suicide prevention telephone number, have been adopted by the government on a national scale. Barcelona City Council has also signed a protocol with employers and trade unions to improve prevention in the workplace, developed a program to help young children develop their "emotional muscles" in schools, and opened crèches between 4.30 and 8 p.m. so that grandparents looking after their grandchildren can get together and help each other. During both of her mandates she championed the idea of (lit. 'superblocks',
city blocks), consisting of a grouping of city blocks to create a bigger one with its interior streets
pedestrianized, especially at
Eixample and
Sant Martí districts; the first iterations were deployed in the
Sant Antoni neighborhood in 2016. During her second mandate she kickstarted the union of
the two tramway networks (
Trambaix and
Trambesòs) along
Avinguda Diagonal, with the first section reaching
Verdaguer (from
Glòries) being opened in November 2024. ==Catalan independence and pro-Europeanism==