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Heathrow Third Runway Litigation – High Court Hands Down Judgments

The Heathrow Third Runway Litigation comprised five claims for judicial review challenging the Secretary of State for Transport’s decision to designate the Airports National Policy Statement (“ANPS”). 

In four claims, the claimants comprised the London Borough of Hillingdon (in which Heathrow is situated) and four adjacent boroughs, the Mayor of London, several non-Government organisations dedicated to environmental causes (notably Greenpeace, Friends of the Earth and Plan B Earth) and one individual claimant (Mr Spurrier). They each opposed any expansion of Heathrow.

The fifth claim was brought by the promoters of a rival Heathrow scheme, which would double the length of the existing northern runway to allow it to operate as two independent runways (“the ENR Scheme”).

On 1 May 2019, the court handed down two judgments, one dealing with 22 grounds of challenge in the first four claims (set out in Annex A to that judgment); and the second judgment dealing with the five grounds of claim in the fifth claim.

All of the claims were dismissed.

The main grounds of challenge in the first four claims fell within the following categories: climate change [558-660], air quality [220-285], surface access [185-219], noise [464] and habitats [286-373]; and, in the fifth claim, legitimate expectation and anti-competition.

Summary of the judgments

First four claims ([2019] EWHC 1070 (Admin))

Climate change

The claimants argued that the Secretary of State acted unlawfully by not taking into account the Paris Agreement – which seeks to hold the increase in global average temperature to “well below” 2ºC above pre­ industrial levels and to pursue efforts to limit that increase to 1.5ºC [602]. In making these arguments, the claimants faced an overarching difficulty which, in the event, they were unable to surmount. The Paris Agreement does not form part of UK law and so, while the UK has ratified it [576], until Parliament decides if and how to incorporate the Paris Agreement target, it has no effect in domestic law [606]. The Climate Change Act 2008 currently sets a carbon cap emissions limit. Under section 2, the Secretary of State has the power to amend that domestic law to take into account the Paris Agreement [567]. However, the court found that the Secretary of State did not arguably act unlawfully in not taking into account the Paris Agreement; and, in any event, at the DCO stage this issue will be re-visited on the basis of the then up-to ­date position [648]. The court held that none of the climate change grounds was arguable.

Air quality

The claimants’ main grounds were that (i) in concluding that the NWR Scheme could be undertaken without breaching the UK’s obligations under the Air Quality Directive, the Secretary of State failed to apply the precautionary principle [261], (ii) the Secretary of State acted irrationally by adopting a policy that was probably undeliverable within those Air Quality Directive [266], and (iii) the Secretary of State relied upon unjustified assumptions about the deliverability of public transport schemes and the effectiveness of Clean Air Zones [269]. The court found that none of those grounds was arguable either.

Surface Access

The claimants submitted, first, that the Secretary of State failed properly to take into account new information and analysis relevant to the surface impact of the NWR Scheme in terms of the adverse impacts of the scheme as a result of more people travelling to and from Heathrow by road [202]. The court concluded that the Secretary of State had had adequate regard to the matters relied upon [208]. Second, it was submitted that the Secretary of State erred in adopting mode share targets (for the proportion of surface journeys that would be made other than by road) that were unrealistic [210]. The court concluded that this was not arguably so [215-219].


In the context of Strategic Environmental Assessment (“SEA”) [374-502], the claimants argued that the noise assessment was inadequate because (i) it used incorrect indicative flight paths [465], and (ii) an incorrect decibel level for determining adverse noise impacts. The court rejected those arguments because

(i) the Secretary of State had an “enhanced margin of appreciation” and was entitled to reach a judgment on the flight paths which were likely to be used [475-477] [487], and (ii) expert evidence explained why the 54dB rather than 51dB level was used. The Secretary of State’s selection of noise parameters was not open to legal challenge [491]. The court found two of the grounds arguable but not made good; the others were not arguable,


It was submitted that the Secretary of State acted unlawfully in not treating the Gatwick 2R Scheme as an alternative to the NWR Scheme for the purposes of articles 6(3) and 6(4) of the Habitats Directive. This was argued on the basis that (i) the Secretary of State’s approach to choosing the objectives of the ANPS was unlawful (namely maintaining the UK’s EU aviation ‘hub status’) and (ii) there was no evidence to form the view that the Gatwick 2R Scheme would cause harm to a Special Area of Conservation upon which a priority species was present. The court allowed permission to proceed on both grounds, but dismissed them on their merits. The court held that it was not unlawful for the Secretary of State to prefer a scheme on the basis that it would maintain the UK’s hub status and it was within his discretion to conclude that Gatwick did not fulfil this aim and so was not a true “alternative” [355]. On the second sub-ground, whilst the court found that there was not sufficient evidence found that the Gatwick 2R Scheme would cause harm to a Special Area of Conservation, this was not determinative as Gatwick had already been ruled out on the basis that it did not meet the hub status requirement [370-371].

Fifth claim ([2019] EWHC 1069 (Admin))

The claimants argued that the Secretary of State had wrongly preferred the NWR Scheme promoted by the owner/operators of Heathrow (“HAL”) over the ENR Scheme promoted by the claimants. The claimants contended that the reasons for preferring the NWR Scheme over the ENR Scheme as stated in the ANPS were “manifestly bogus”, and that the real reason for preferring the NWR Scheme was because the Secretary of State had sought from HAL an assurance or guarantee that if he chose the ENR Scheme HAL would implement it, which HAL had not provided. It was contended that this reason for preferring the NWR Scheme infringed a legitimate expectation in the claimants and also infringed articles 102 and 106(1) TFEU (the Treaty on the Functioning of the European Union). The court rejected these arguments.

The contention that the claimants had a legitimate expectation that the Secretary of State would not take into account, in the decision to prefer the NWR Scheme, the absence of an assurance from HAL that it would build the ENR Scheme if it was preferred failed for three reasons: (i) there was no such legitimate expectation created by the Secretary of State; (ii) had there been a legitimate expectation (which there was not), the Secretary of State was entitled to resile from it; and (iii) in any event, the absence of an assurance or guarantee from HAL regarding the ENR Scheme was not material to the preference decision. This was Ground 2 of the claimants’ challenge. Ground 1 – which was a competition law point based on the TFEU, but on similar facts to Ground 2 – failed for similar reasons; although the court also identified further reasons why this ground would fail under EU competition law. In respect of both of these grounds, the court granted permission to apply but found the grounds had not been made good.

The court rejected the argument that the NWR Scheme had been preferred for reasons that were “bogus”. It also rejected Grounds 4 and 5 of the claimants’ challenge and found that these challenges (relating to two of the three reasons for preferring the NWR Scheme) were unarguable. The claimants’ challenge to the third reason in the ANPS for preferring the NWR Scheme was abandoned by the claimants prior to the hearing.

In all claims, Michael Humphries QC of Francis Taylor Building and Richard Turney of Landmark Chambers appeared for Heathrow Airport Limited instructed byTim Smith of Bryan Cave Leighton Paisner LLP.