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Heathrow expansion – halted or merely delayed?

The Court of Appeal’s recent decision that the Airports National Policy Statement failed to take into account the Paris Agreement on climate change has left campaigners celebrating.

But does it really spell the end for Heathrow’s expansion plans or is it simply a delay? What are the implications for other major infrastructure projects?


In December 2015 the Paris Agreement was adopted by the participants in the United Nations Framework Convention on Climate Change, including the UK. It required each signatory state to determine its own contribution to mitigating climate change.

In June 2018 the “Airports National Policy Statement: new runway capacity and infrastructure at airports in the South East of England” (ANPS) was designated by the Secretary of State for Transport under the Planning Act 2008. The ANPS contained no mention of the Paris Agreement.

The decision to designate the ANPS was challenged by a mix of environmental NGOs, London boroughs and the Mayor of London. After their claims were rejected by the Divisional Court in May 2019, three sets of claimants were given permission to appeal to the Court of Appeal.

The climate change issue

The claimants argued successfully that the government’s commitment to the Paris Agreement constituted government policy on climate change, which the Secretary of State was therefore required to take into account in making his decision to designate the ANPS. It was common ground that the Secretary of State had not taken the Paris Agreement into account in making the designation decision.

The government argued that its policy on climate change was as set out in the Climate Change Act 2008. It had received legal advice that not only did it not need to take the Paris Agreement into account, but it could not lawfully take it into account. The court disagreed with this approach, stating that the concept of policy was necessarily broader than legislation. At the time the ANPS was designated, it was the government’s expressly stated policy that it was committed to adhering to the Paris Agreement.  The court also noted that the duty in the Planning Act did not require the government to conform to its policy commitments, but simply to take them into account and explain how it had done so.

Rather than quashing the ANPS, the court made a declaration that the ANPS has no legal effect unless and until the Secretary of State decides to review it. The government (which has indicated that it will not appeal the decision) has not yet indicated a timetable for this.

In spite of the campaigners’ celebrations, the decision is unlikely to mean the end of Heathrow’s expansion plans.  The government now has the opportunity to correct its error by reviewing the ANPS and taking into account its policy commitments under the Paris Agreement. Heathrow Airport Limited (an interested party in the proceedings) may also decide to try to appeal to the Supreme Court.

Wider implications

There has also been speculation that the decision may mean more legal challenges to, or delays or cancellations of, other major infrastructure projects. Indeed, the naturalist Chris Packham has recently announced that he intends to challenge the decision to proceed with HS2.  However, this optimism may be misplaced. As the court pointed out, the government merely needs to take into account its policy commitments; it is not required to act in accordance with them. A project may still proceed even if the Paris Agreement commitments are considered and disregarded for other reasons.

The court also stressed that its decision was not a political one about how and whether Heathrow should be expanded. It was a legal decision as to whether the Divisional Court was wrong to conclude that the process by which the government produced its policy in favour of Heathrow expansion was lawful. These remarks may well have been made with regard to the government’s impending constitutional review, following the Conservative Party’s 2019 election manifesto pledge to ensure that judicial review ‘is not abused to conduct politics by another means or to create needless delays’.

R (on the application of Plan B Earth) v Secretary of State for Transport; R (on the application of Friends of the Earth Ltd) v Secretary of State for Transport; R (on the application of London Borough of Hillingdon Council and others) v Secretary of State for Transport [2020] EWCA Civ 214


This information is for educational purposes only and does not constitute legal advice. It is recommended that specific professional advice is sought before acting on any of the information given. © Shoosmiths LLP 2022.


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