In 2015, I heard that a crowdsourced citizens’ platform elected a new mayor in Barcelona. Activists had formed a grouping of electors, a temporary group of citizens aiming to forward a candidate in a specific election, even without a political party. Drawing on mass movement assemblies, they developed a new citizens’ platform called Barcelona en Comú (Catalan for “Barcelona in Common,” abbreviated as BComú). BComú won enough votes to appoint Ada Colau as mayor. Until then, Colau had been an anti‑evictions activist and founding member of Plataforma de Afectados por la Hipoteca (Platform for People Affected by Mortgages), which used both policy campaigns and nonviolent direct actions for housing reforms.
I was struck by BComú’s refusal to choose between process (insisting on “real democracy”) and outcomes (greater resources for social policies). In two terms, BComú quadrupled the budget for social housing and recovered €150 million in corporate tax revenues. It formed a municipal childcare program, sustainable public energy company, publicly owned dental clinic, the city’s first municipal LGBTQ center, and new systems for city procurement to source from solidarity economy cooperatives. Also, it allocated funds to new cooperatives, especially migrant- and refugee-led ones, and halted fines on sex workers. [1]
BComú declared that “we took the social networks, we took the streets, and we took the squares … to win back the city,” but wanted to change how city hall operates as well. [2] Still, while Colau’s administration made significant strides for budget justice in Barcelona, it lost local elections in 2023.
I was eager to glean lessons from BComú’s experiences and spoke with Marc Serra Solé over Zoom about what he had learned. In 2019, Serra Solé was elected councillor for citizen rights and participation on the Barcelona City Council, a position he held until 2023. He also served as secretary general of the International Observatory on Participatory Democracy. Serra Solé is deputy area chair for climate action and energy transition as well as deputy councillor for citizens’ participation on the Barcelona Provincial Council.
This interview has been edited and condensed for clarity and concision.
Celina Su : The case of Barcelona is remarkable for moving beyond established political institutions and electing a mayor out of a platform instead. Why do you think this came about ?
Marc Serra Solé : What happened in 2015 in Barcelona—and in many other cities around Spain—was incredible. Citizen candidates, such as BComú, ran in elections for the first time and won. And we did it without having media or financial support.
There are two [main] reasons. [First,] the erosion of the Spanish two-party system : the two large parties that have alternated power in Spain for the last 40 year were in crisis. Second, the Indignados movement that occupied the squares, seeing that its proposals were not listened to by the large parties, forwarded citizen candidacies with broad social support.
The victory of BComú is also explained by the leadership of Ada Colau. With Ada, we gathered academics, lawyers, and activists, all active in city movements, and from there emerged BComú. We were generating a new political space in which citizens could participate with the maximum of internal democracy, without electoral quotas or coalition agreements.
How did this “maximum of internal democracy” develop ? Sometimes, progressive movements lose support because they’re not engaging the public well, or doing things on behalf of people and not with people. How did you work to avoid this ?
It was important that all the little political parties, like left-wing and environmental parties, were committed to this new space—without controlling it. Everybody had to deliberate on each issue.
BComú was created in 2015, and the elections were in 2016, so in just one year we created a group and won elections. So our issue was, Let’s prepare for the elections with open assemblies in the neighborhoods to create the candidate’s political program. We did that using open assemblies.
This assembly culture was very important for citizen participation and connected everything we did. Everybody says, “I was there in 2011, when citizens occupied the squares.” And now we approached the [BComú] platform in this same way—not as [a typical] protest, not to take command of [existing] institutions, but to articulate new terms.
We made sure that leaders of existing movements agreed that it was an important moment to seize the institution [of elected office]. We worked on ensuring mass participation—not just by top [or] medium-level advocates [but also rank-and-file people in grassroots movements along with everyday citizens]. Here were people who have been fighting for the last 20 years in social movements, who want a change in the city. We needed to earn their trust, for them to say, BComú could be a good tool to build power ; it feels different from the city council.
The city’s Decidim and PB initiatives since then have received a lot of attention. Did they help make the city budget more democratic ?
When we won the elections, we promised that we would not [single-handedly] develop the Municipal Action Plan as long as we held office. [This plan is the traditional policy road map for each new term.] We wanted it to be prepared in a participatory manner by as many citizens as possible. So we created Decidim, an online platform for citizen input. In the beginning, the platform helped thousands of people to make proposals and interact with one another, critiquing and improving proposals. It aimed to be a complement to deliberation and in-person participation. Forty thousand citizens participated in this process, making around 10,000 proposals that had 156,000 supporters—figures that were unprecedented in the city’s participation system.
We soon saw that the Decidim tool had so much potential that it could have more functionalities and transcend Barcelona. The fact that we had created it with free, open-source software allowed us to share it with other cities that could also make improvements, providing feedback on the tool. [This contrasts with the typical practices of hiring private contractors.]
And we inaugurated participatory budgets [PB] here in 2020. The PB process in Barcelona served us most through a lot of teaching on how public investment works in the neighborhoods and generating a democratic culture, especially in sectors that were not [previously] organized. For example, citizens saw this tool as an opportunity to achieve improvements in their schools, small sports facilities, parks, bike lanes, and so on. It also served as a powerful experience of collective intelligence and innovation because among the 2,000 projects that citizens proposed, there were some that would never have arrived via traditional spaces of policymaking.
Beyond specific institutional designs, what cultural connections do you see between radical democratic practices and Barcelona’s political trajectory ?
Barcelona has a long history of worker, neighborhood, and feminist movements. The cooperative movement, starting in the late 19th century, managed to build a parallel society of production and consumption athenaeums and cooperatives to respond to the needs of workers. [These athenaeums have been likened to citizenship schools in the US civil-rights movement, operating in contexts where access to formal education remained limited. [3]]
There is definitely some continuity between the cooperative, anarchist history of the early 20th century and the democratic radical movements from these last 20 years. Both are sets of movements that try to oppose the havoc caused by savage capitalism—whether in the form of Fordism or its digital version, in the form of platforms such as Amazon or Uber. People see how the liberal democratic system is as incapable of providing answers to inequalities or channeling the desires of a social majority for emancipation.
Through the city government, we have promoted the democratization of the economy through cooperativism. In the last eight years, the number of cooperatives has increased by 55% [with women constituting 60% of workers and worker-owners], and today, Barcelona has Can Batllò, the largest cooperative center in Europe.
You say that the public sees “how the liberal democratic system is incapable of providing the answers to inequalities.” How did citizens in Barcelona see the limits of the liberal democratic system and turn to cooperative efforts ?
You have the market, you have state institutions, but then you have the citizens, or as we say, la comune, the community. We have a lot of associations, around 5,000 in the city, and a lot of public facilities that are important to community. For example, we have 73 neighborhoods, with public civic/social centers in each.
More than 50 of these neighborhood centers are autogestionados [self-determinations]—civic centers, athenaeums, sports facilities—managed directly by groups of citizens. These public facilities today reflect the radical democratic story of Barcelona—even when that history is quite unknown to the social majority. We see the same practices of self-management, cooperativism, and mutual support. It’s a revindication that citizens want the community [to] have spaces to develop projects with the support of the public administration, but the leadership of the community.
In your view, what are BComú’s greatest accomplishments and challenges ?
From the city government of BComú, we increased the budget for social rights by 74%, placing Barcelona as the administration in Spain with the greatest social investments. This facilitated the development of new rights such as energy advice, psychologists, and public dentists, which are now progressively assumed by the state or regional government.
Likewise, we achieved a 62% increase in the budget for education and culture, which enabled the opening of 50 new public schools, so that public education offerings in the city now exceed private ones. Public transport has also been a priority : fares have been frozen for the last six years, and the budget has been increased by 85% to improve our network. The housing budget has increased by 68%, so that the Barcelona administration is the country’s leader in new public housing construction. Likewise, we created an anti-eviction unit (focused on mediation and social support) that managed to stop 93% of evictions.
Still, there remain challenges. Rents increased by 50% in recent years throughout the country. This means that [even our increased] social investments have often not been enough to help many families to make ends meet. Social movements, with the support of BComú, have been insisting for years on the need to regulate rental prices, prohibit abusive increases, and protect tenants. Finally, and after overcoming the resistance of the real-estate lobby in 2023, we passed a new housing law to cap rental prices. This has been, without a doubt, one of the main battles of the last decade, and the challenge will be for new administrations to actually enforce the law and burst the speculative bubble.
Where did the money come from for these investments ?
In Spain, local administrations have significant problems with funding because we don’t manage most taxes ; the main ones are at the regional and federal levels. So we do different things ; for example, each tourist who sleeps in Barcelona now pays around three euros per day, much more than before. It doesn’t sound like a lot, but it’s important. [In 2022, there were around 10 million tourists and 30 million overnight stays in Barcelona.] Then we work toward agreements with the state or federal governments for some of these projects, especially when our political party is holding the majority at those levels.
This reflects our priorities. Maybe other governments [prioritize] other activities, like promotion of tourism. We spent so much money on selling the city, telling everybody in the world to come to Barcelona. We reduced that part of our budget ; our investments focused instead on social provisions. We also increased property taxes in a progressive way, asking those who own big properties to pay just a little more, and increased transaction fees for estate transfers and property sales.
What are some of your key challenges now, especially in the face of rising authoritarianism worldwide ?
Making sure that progressive forces are those framing the problems to be addressed, in ways that resonate with the social majority. If I have learned anything from politics, it is that ideas are ultimately judged by their ability to concretely improve people’s quality of life and generate new rights. Radical ideas are of little use if they do not manage to be shared by a social majority and get translated into public policies that, in turn, transform social reality.
During and after the 2007 financial crisis, we were the ones to define and frame the crisis : We are the 99%. And we have problems with the 1% ; we are the people with problems with jobs, evictions. From 2008 to 2015, this framing helped garner social support for progressive proposals.
[In some ways, that framing continues to resonate.] Defending the right to the city in Barcelona today means protecting it from international investment funds that see the city as a commodity—purchasing entire residential buildings, renovating them, and renting them at exorbitant prices, especially as tourist rentals. Many families are being displaced from their neighborhoods and even the city because they cannot afford rent.
[But in other ways,] we have a different political moment now. Progressive movements are not the ones [forwarding popular] frameworks ; now it’s the far right. The same families facing evictions now say that immigrants are their enemy, not market speculation. [We have to work to not only attain power but maintain it too.] The current mayor beat Ada by only 200 votes. There was no runoff election.
Amid all of this, what is to be done for budget justice—in Barcelona and elsewhere ?
Without BComú in government, the new administration immediately questioned the continuity of the participatory budgets. Those selected projects that open up public spaces in the city—such as bike lanes or street pacification—are being canceled by the new government. [Meaningful institutions are never permanently won ; they have to be won over and over again.]
I don’t think, however, that the city’s organized citizens will allow this to happen. Neighborhood associations and social groups have already been organizing to demand that the new government respect the will of the thousands of residents who voted for the winning projects. This is one of the neighborhood struggles that is really galvanizing citizens around the city.
This piece is an extract from Budget Justice : On Building Grassroots Politics and Solidarities (© 2025), published by Princeton University Press and reprinted here by permission.
