Photo: Demonstration against the expansion of El Prat airport, September 2021 (Foto: Marc Garcia)

An article by Franziska Schmidt, with input and feedback from Ariadna Cotén, Zeroport. This article is the result of desk-based research and an interview with Ariadna in June 2025. An important source was an academic paper on the conflict by Sara Mingorría and Ariadna Cotén which was based on analysis and reflections from internal debates within Zeroport and public contributions from members of Zeroport and Stay Grounded.

The decades-old conflict around El Prat airport and the destruction of the Llobregat Delta is one of Europe’s most important environmental justice struggles. The conflict entered a new stage, with airport expansion plans being put back on the table in June 2025.

The proposal threatens the internationally important La Ricarda and Remolar Wetlands and would bring even more intercontinental flights and cruise passengers, further cementing Barcelonaas a hub for mass tourism.

The resistance to this airport project is being led by Zeroport, a diverse coalition of over 150 grassroots organizations, including neighbourhood associations, environmental NGOs, farming cooperatives, climate justice groups and anti-touristification movements. They united around the interconnected themes of overtourism, just urban development and territorial defence and successfully reached out to related struggles elsewhere.

The conflict and mobilisation had culminated when yet another huge extension was announced in 2020. Activists achieved a 5-year expansion freeze in September 2021, but have not been idle: They used the interim to consolidate alliances, connect with regional politicians and educate themselves about other related struggles. Their steady, persistent grassroots organising (what they call ‘ant work’) rather than explosive short-term campaigning anticipated the June 2025 expansion proposal and Zeroport was ready to launch the next round of mobilisation. Crucially, they have two Catalan coalition parties and the European Union’s environmental regulation on their side. What can be learned from the rich history of this struggle?

El Prat in Context

El Prat Airport is situated within the internationally important Llobregat Delta wetland, which enjoys protection under the Natura 2000 network scheme. The delta is not only home to rare wildlife, but also provides drinking water, natural flood control and some of the Mediterranean’s most fertile soils.

Since it was opened in 1918, the airport’s ever-faster growth has gone hand in hand with the development of the nearby port facilities and the advent of mass tourism in Barcelona. The huge Delta Plan extension added a third runway, in 2004, and a new terminal, in 2009, along with an enlargement of the port. It brought total yearly passenger capacity to 55 million and increased the destruction of the Llobregat Delta. In combination with the port expansion, new roads, highways and urbanization lead to 60% of the Delta being concreted over.

Opposition to the delta’s degradation, meanwhile, is decades-old and has historically brought together neighbourhood associations, farmers and environmental groups. These networks formed an important cradle of resistance when yet another expansion plan began to loom in early 2020.

The objective of the government is to transform El Prat into an “international hub” of 70 million yearly passengers and they want to extend the third runway into one of Catalonia’s most important ecological zones, home to 20 EU-designated special conservation areas. Businesses and organisations of employers hailed the plans as a leap toward economic progress, through attracting more intercontinental flights, arguing that a gateway to Asia and easier access for international tourists were needed.

Alongside powerful government, business and lobby support, huge economic interests lurked behind the plans: AENA’s shareholders include BlackRock, Vanguard and Deutsche Bank.

Resistance Takes Off Again

Civil society, however, was ready: Within months, a diverse group of actors ranging from environmental organisations, neighbourhood assemblies, climate justice collectives, and anti-touristification platforms through to degrowth advocates joined forces to form Zeroport.

From the beginning, the network linked aviation growth to tourism-based gentrification, property speculation, and social inequality. In this way, they spoke to multiple audiences and avoided narrow and easily dismissable labels like “Not In My Back Yard” (NIMBY-ism) or eco-dogmatism.

The group also positioned itself against the continued enlargement of the Barcelona port, linking the two as interconnected engines of climate and over-tourism. Zeroport activist Ariadna Cotén explains: “They want to expand the airport because they want to bring in more intercontinental flights. And on the other hand, the port authority wants more and bigger cruise terminals. The connection is tourism, as it is a central element that links everything together“.

Mass Mobilisation

After a lull during the pandemic, things unfolded rapidly in 2021: In June, AENA pushed to include the El Prat expansion in Spain’s 2022–2026 airport infrastructure plan, DORA II. This would lock in national government approval and make the expansion a priority project.

Swift action was crucial: The regional government was undecided about the issue, with the Catalan elections a mere 18 months away. Zeroport launched an intense campaign of organising, media outreach, and local assembly-building. Activists went to neighbourhoods throughout the city to talk about touristification, thereby establishing a link with residents about the issue of the airport. They also built links with campaign groups opposing other mega-projects within Catalonia, such as a resort casino near Tarragona (Aturem Hard Rock) and a new ring road around Barcelona (Aturem B40).

Amidst disagreements between the ruling coalition and vocal public backlash, another long-planted seed of resistance bore fruit: In 2012, Catalan environmental NGO Depana had filed a formal complaint about the airport’s destruction of protected lands. In February 2021, the European Commission finally stated that previous airport developments had indeed violated Natura 2000 protections. Brussel’s firm warning to the Spanish government demanded they extend the Special Protection Area for Birds and comply with protective measures. In September, the Spanish Transport Minister announced that the project had been ‘paused’.

Despite the official suspension, activists wanted to emphasise that they wouldn’t accept a quiet revitalisation of the project later on. Thus, on 19th September 2021, Catalonia’s largest post-pandemic demonstration took to the streets in Barcelona. Neighbourhood groups, environmental NGOs, farmers’ unions, climate justice collectives, such as Fridays for Future and Greenpeace, and activists fighting other mega-developments in Catalonia all attended, demonstrating Zeroport’s wide base and extensive network.

Ariadna reflects: “This outreach work is very important because when we held the demonstration, the only way to make it powerful was to have columns coming from all over: there was a column coming from the Llobregat Valley which filled the entire motorway… and this was very powerful.”

Consolidating the Movement

During the 2021 political and media frenzy over the expansion, Zeroport grew rapidly from 35 to 140 groups. After the 2021 peak, a core remained active in the coalition, with most returning to their local struggles. When things quietened down in 2022 and 2023, Zeroport cleverly shifted its focus: The platform invested in political education and expanded its network beyond Barcelona, strengthening its alliances with movements opposing other Catalan mega-projects.

This culminated in the “Defensem la Terra” mobilisation, which united thousands across Catalonia against extractivist developments and speculative urbanism. Ariadna explains: “The only way to build power is to support other struggles when they need it – and they’ll support you when you do.” Regular events also helped to maintain momentum and keep the issue alive in the public consciousness.

Another example of coalition-building manifested in 2024, when Zeroport aligned with pro-Palestinian and anti-militarist organisations to protest the Aviation Week in Barcelona. This convergence broadened the narrative, showing the connection of aviation not just with environmental degradation, but with colonialism, racism, militarism and the destruction of cities.

Mural “Less planes, more life. Fighting for climate, health and life (Photo and art by Rock Blackblock)

The Next Phase

“We were clear that when the expansion was halted in 2021, after four years we would have the project back on the table, because they don’t rest. Not just AENA and the politicians, the employers’ association, in 2022, already started working on the expansion”, says Ariadna.

Indeed, the 2024 election brought a crucial political shift: the Socialist Party of Catalonia (PSC) came to power in September, explicitly championing expansion as “essential for the Catalan economy.” The imminent closure of DORA II (2021–2026), the key regulatory framework for airport investments, and renewed business lobbying added further momentum.

Thanks to their sophisticated understanding of the political landscape, Zeroport has anticipated developments and used the long lull to focus on outreach. Campaigners have been in ongoing dialogue with left and centre-left parties opposed to the expansion. Two of them, Comuns and ERC, form the new coalition government alongside PSC. The investiture agreement with ERC (Republican Left of Catalonia) includes a binding emissions cap aligned with European Green Deal goals – a commitment activists now intend to hold the party to.

When Catalan president Illa announced a new €3.2 billion expansion plan in June 2025, the response was swift: Over 300 organisations – including environmental, academic, agricultural, neighbourhood, and scientific groups – condemned it in a public statement. ERC and Comuns publicly condemned the plan, with the Comuns hoping Brussels will block it on environmental grounds.

As the activists had anticipated all along, the fight is far from over. The next phase of their resistance will focus on:

• Blocking the new DORA III (2027–2031) infrastructure plan
• Demanding compliance with emission limits negotiated by ERC in the 2024 investiture agreement
• Creating political contacts and pressure with parties like Comuns and CUP
• Organising new mobilizations to keep the issue in the public and political spotlight
• Enhancing European Union pressure around the Natura 2000 infringements

Ariadna remains hopeful, both for Zeroport and for other movements: “No matter how much it seems like you are fighting against very complicated, very large and very powerful infrastructures and lobbies, in the end, if you play your cards right, you can do quite a lot.”

Lessons Learned – What Worked in the Fight Against El Prat?

Building broad alliances: Rural, urban, social, and ecological movements joined forces. Zeroport also reached out to other struggles, using mass tourism and territorial defence as the common denominator

Use inclusive narratives: The fight became not ‘just about a runway or a wetland’ but about climate, housing, tourism, and justice.

Be prepared for the long game: Electoral cycles and political alignments shift, but sustained organising creates leverage. Activists used quiet periods for training and outreach.

Choose strategies wisely: Zeroport combined long-term coordination (“ant work”) with rapid mobilisation and symbolic actions when needed.

Engage all levels: Connecting with local councils and regional parties has amplified leverage.

Play the political field: Using strategic timing and pressure points can achieve a lot, says Ariadna: “It’s about understanding which parties support what, which don’t, which party you can push a little harder, and when. Because this also varies depending on the moment.“

Utilise legal tools: The EU’s 2021 letter of notice remains valid, creating an important pressure point.

Connect with international support: Global networks like Stay Grounded provide visibility, solidarity, and strategic inspiration.

Red Line to Aviation Growth and Mass Tourism at El Prat Airport in July 2016 (Photo: Christine Tyler / Stay Grounded)