Nutrient neutrality in the Supreme Court

On 22 October 2025, the UK Supreme Court handed down its judgment in C G Fry & Son Ltd v Secretary of State for Housing, Communities and Local Government.  

At issue was a proposed mixed use development of 650 dwellings and associated infrastructure in Somerset. The development site is in the catchment area of the River Tone, which feeds into the Somerset Levels.  

Outline planning permission had been granted for the development in 2015, and reserved matters approval (RMA) for phase 3 of the development followed in 2020. However, when CG Fry applied to discharge conditions attached to the RMA, the LPA withheld its approval. This was based on updated advice from Natural England regarding phosphate loading and its potential impact on the Somerset Levels and Moors Ramsar site (Ramsar site). The LPA relied on paragraph 181 of the NPPF (now paragraph 194) and maintained that an appropriate assessment (AA) was required before the conditions were discharged.  

The case raised two principal legal questions:

1. whether an AA under the Conservation of Habitats and Species Regulations 2017 (Habitats Regulations) is required under subsequent stages of the planning process following planning permission, including the approval of reserved matters and the discharge of conditions
2. the effect of a grant of outline planning permission, and what is the impact on that grant of a policy adopted by the Government and a change of scientific advice bearing on the application of that policy.

CG Fry challenged the LPA’s decision at a planning appeal, in the High Court and then the Court of Appeal, with the appeal being dismissed in all three cases. The case then went to the Supreme Court (SC).

The Supreme Court’s findings

On the first issue, the SC unanimously upheld the decisions of the lower courts. It confirmed that regulation 63 of the Habitats Regulations applies not only at the stage of granting planning permission, but also at subsequent stages of the planning process, including the discharge of conditions. It held that where new scientific evidence emerges, such as Natural England’s 2020 advice on phosphate impacts, competent authorities are obliged to undertake an AA before authorising further development.

However, on the second issue, the SC allowed the appeal on the basis that the Habitat Regulations don’t legally apply to Ramsar sites – the protections are only afforded to Ramsar sites pursuant to the NPPF which cannot override the legal rights conferred by a grant of planning permission.  

Implications for LPAs and developers

While being of relevance to specific environmental protection issues (although see our concluding paragraph below), this judgment is also notable as it discusses the critical distinction between the legal force of planning permissions and the status of national policy, and highlights the importance of carefully considering and interpreting planning conditions.

The Court reminded us that “rights given by the planning legislation cannot be overridden or diluted by general policies laid down by central government, whether in the form of the NPPF or otherwise”. The SC drew heavily on the principle that the planning system should incentivise landowners to proceed with developments by limiting the extent of risk they take on. LPAs may only withhold approval in relation to matters expressly reserved or set out in conditions. If a change in policy means that the LPA wishes to revoke or modify a permission already granted, legislation provides a statutory right to compensation (s107 of the Town and Country Planning Act 1990). This allows developments to come forward without fear of permission being later revoked due to a change in policy or to further objectives that are unrelated to the conditions imposed on it. LPAs must, therefore, exercise caution when seeking to rely on evolving policy or scientific advice to revisit permissions already granted, particularly when withholding approval for discharge of a condition that bears no relevance to the objective of the policy concerned. 

Looking ahead: The Planning and Infrastructure Bill (PIB)

Developers should be aware that new planning legislation may close the gap relied upon by the developer in this case in relation to the ongoing assessment of impacts on Ramsar sites. Schedule 6 of the PIB, as currently drafted, has the effect of granting Ramsar sites the same legal protection as sites covered under the Habitats Regulations. If passed in these terms, rather than relying on policy, the PIB would enable LPAs to lawfully refuse to grant permissions and approvals relating to Ramsar sites, including discharge of conditions, until an AA (or further) is conducted. This means that developers should continue to remain alive to risks (and delays) arising well beyond the initial grant of planning permission. 

The PIB has reached the report stage in the House of Lords and was considered again on 27 October (although the House hasn't, at the time of writing, yet considered this amendment).

A full copy of the judgment can be found here.