Press release

Portugal abandons plans to build new airport on nature reserve following lawsuit

Alternative airport location will still have far-reaching impacts on people and the environment, say environmental groups

16 May 2024

Environmental lawyers have reacted after the Portuguese government announced it would abandon plans to build Lisbon’s new airport on an internationally protected nature site, following a long-running legal case against it.

Lawyers from ClientEarth and Sociedade Portuguesa para o Estudo das Aves (SPEA, BirdLife Portugal), along with eight Portuguese NGOs, had launched a lawsuit to stop the plans to build the capital’s new airport on the Tagus Estuary, Portugal’s most important wetland and a crucial safe haven for millions of migratory birds.

The plans provoked national and international outcry from scientists and the general public, and the lawsuit received the backing of Portugal’s Public Prosecutor – driving the Portuguese authorities to review and eventually drop the plans. The announcement made by Prime Minister Luis Montenegro means that the Montijo airport on the Tagus Estuary will no longer go ahead – but a new airport will instead be built at an alternative location near Alcochete.

Head of ClientEarth’s Iberian and Mediterranean office, Soledad Gallego, said: “It is unbelievable that the Portuguese authorities were considering building a new airport on this protected site. The airport would have significantly deteriorated the habitats of this irreplaceable nature reserve and seriously compromised the migratory route from Europe to Africa of birds that depend on this unique area for survival. The decision to abandon building on the Tagus was the only feasible route to take.”

The groups, who launched their legal action in 2020, argued that the Portuguese authorities failed to properly consider the severe impacts of the future airport on protected migratory birds and habitats found in the Tagus before giving the project the green light.

Failure to fully assess the environmental impact of a project, and jumping to suggesting that birds can and will simply inhabit nearby sites instead, is a clear breach of EU and national laws.

Gallego added: “The authorities have clearly realised that building the airport on this internationally protected site would be incompatible with tackling the biodiversity crisis we are facing. The knock-on effects that this project would have had on migratory birds would have been felt well beyond Portugal’s borders.

“But airports have global climate impacts regardless of where they are built. The Portuguese government should be asking itself whether building a new airport at all is in line with its climate goals and in the best interest of the health of people and nature.”

Following the launch of the groups’ legal action, the Portuguese authorities announced they would carry out a Strategic Environmental Assessment (SEA) to determine the most appropriate location for the new airport. The announcement made by Prime Minister Montenegro to now build the airport near Alcochete is the outcome of the SEA.


Notes to editors:

National environmental groups supporting SPEA and ClientEarth’s legal action are: Liga para a Protecção da Natureza (LPN), Associação Natureza Portugal (ANP|WWF), ZERO – Associação Sistema Terrestre Sustentável, Fundo para a Protecção dos Animais (FAPAS), Grupo de Estudos de Ordenamento do Território e Ambiente (GEOTA), Associação de Defesa do Património Cultural e Ambiental do Algarve (Almargem) and Associação Cristã de Estudo e Defesa do Ambiente Cruzinha (A Rocha).

The case is also being supported by international experts and organisations, including the Royal Society for the Protection of Birds (RSPB), BirdLife International and BirdLife Netherlands.

Regional background

The new airport would have been located in the Tagus Estuary, close to Portugal’s capital. It is one of the main estuaries in Western Europe and is Portugal's most important wetland for waterbirds. The area that would have been affected by the new airport is protected as a Special Protection Area (SPA) and Site of Community Importance (SCI) under the EU’s Natura 2000 network; a Ramsar wetland; and a Portuguese Nature Reserve.

The Tagus Estuary regularly hosts up to 200,000 wintering birds and is the most important place in the country for wintering ducks, waders, and other waterbirds such as flamingos and gulls. Meanwhile, in any given migration season, the Tagus can play host to in excess of 300,000 birds, as it acts as a crucial pit stop for migratory birds on their long journey.

Basis of the environmental groups’ legal action

In January 2020, the Portuguese Environment Agency approved the Environmental Impact Statement (EIS) for Montijo Airport.

In June 2020, ClientEarth and Sociedade Portuguesa para o Estudo das Aves (SPEA, BirdLife Portugal), along with eight Portuguese NGOS, filed a court action with the Lisbon Administrative Court. The environmental groups argued that Montijo Airport’s EIS, which approves the development of the project based on a series of assessments, goes against EU and national law and should be annulled.

An EIS is a document in which the government sets out its assessment of a project’s impact on the environment. EU law requires a series of assessments to be carried out to determine a project’s impact on a protected site. Only after these assessments have been conducted, and show no harm would be caused to the area, can a project go ahead.

Exceptions can only be made when there are no alternative options. In these cases, the authorities must provide a solution to compensate for the damages caused by the project.

In this case, lawyers consider that the Portuguese authorities have failed to carry out reliable assessments and have instead proposed to ‘relocate’ the birds that would be affected by restoring marginal areas of the protected area to compensate for any negative impacts from the airport.

In Portugal, the decision to build Lisbon’s new airport on the Tagus Estuary had been met by public and political outcry. Environmental groups in Portugal also expressed their disapproval, with experts citing the construction as a “crime against nature”.

In the Netherlands, thousands of people signed a petition against the construction, as it would seriously threaten the migratory black-tailed godwit, the Dutch national bird.

About ClientEarth

ClientEarth is a non-profit organisation that uses the law to create systemic change that protects the Earth for – and with – its inhabitants. We are tackling climate change, protecting nature and stopping pollution, with partners and citizens around the globe. We hold industry and governments to account, and defend everyone’s right to a healthy world. From our offices in Europe, Asia and the USA we shape, implement and enforce the law, to build a future for our planet in which people and nature can thrive together.