High Court refuses judicial review over planning inspector’s assessment of protected sites
Natural England advice was given significant weight by a planning inspector when assessing whether a proposed sand and gravel extraction project would harm protected sites, the High Court has ruled.
Mr Justice Chamberlain refused permission for judicial review in Hamble Parish Council v Secretary of State for Housing, Communities and Local Government & Ors [2026] EWHC 2138 (Admin), handed down on 11 August 2026.
The case concerned Cemex UK Operations Ltd’s application to extract sand and gravel from the former Hamble Airfield in Hampshire. Hampshire County Council had refused planning permission, but Cemex appealed and a planning inspector, Stephen Normington, allowed the appeal following a public inquiry.
Hamble Parish Council, a constituent member of the Hamble Peninsular Defence Group, challenged the inspector’s decision under section 288 of the Town and Country Planning Act 1990.
The challenge centred on the potential hydrological effects of the development on European and Ramsar protected sites. Evidence before the inquiry included competing expert assessments about whether removing River Terrace Deposits and replacing them with inert infill could alter groundwater flows and affect habitats and species.
Natural England had initially raised concerns about the potential effect of changes in groundwater flows on the Lincegrove and Hackett’s Marshes Site of Special Scientific Interest. It later did not object to the development and, in September 2024, advised that it had no objection to the appeal scheme subject to specified mitigation measures.
The claimant argued that Natural England’s position had been influenced by an incorrect factual premise about the location of part of the protected site. It also argued that the inspector should have taken further steps to establish whether Natural England had considered the evidence presented at the inquiry.
The High Court rejected that argument. The judgment states that the only statutory duty imposed by regulation 63(3) of the Conservation of Habitats and Species Regulations 2017 was to consult Natural England. There was no statutory duty requiring the inspector to take positive action to draw particular matters to Natural England’s attention.
The court also confirmed the significance of expert environmental advice in these decisions. A competent authority is entitled, and can be expected, to give significant weight to advice from an expert national agency such as Natural England. It may depart from that advice, but must have cogent reasons for doing so.
Importantly for solicitors advising on planning challenges, the judgment confirms that the court’s role in reviewing a regulation 63 decision remains supervisory rather than a reassessment of the underlying planning or scientific merits. Where the competent authority has properly understood its legal duty, the court applies ordinary public law principles and will intervene only for a Wednesbury error.
The court also addressed the legal threshold under regulation 63(5). A competent authority must ascertain that a project will not adversely affect the integrity of the protected site, but this does not require absolute certainty. The relevant standard is that there must be no reasonable doubt as to the absence of adverse effects.
In this case, the inspector had independently assessed the competing expert evidence and concluded that the development would not materially affect groundwater flows to the relevant springs or freshwater flows into the protected sites. He also concluded that any potential change in the hydrological regime would not result in an adverse effect on the integrity of those sites.
Mr Justice Chamberlain found that both conclusions were open to the inspector and adequately explained. The court held that the claimant’s arguments largely sought to reopen issues that had already been considered during the planning inquiry.
The court concluded that none of the three grounds of challenge was realistically arguable and refused permission to apply for judicial review.