Staunch Campaign Limited, R (on the application of) v North Northamptonshire Council

At the appropriate-assessment stage under the Habitats Directive and the Conservation of Habitats and Species Regulations 2017, a competent authority may take account of preventive mitigation that eliminates or reduces harmful effects so that no adverse effect on site integrity remains. Measures that accept harm and merely offset it elsewhere belong to the compensation route. Replacement functionally linked land outside a Special Protection Area can nevertheless be mitigation where the development is outside the protected site and the replacement habitat is secured, enhanced and monitored. Judicial review remains supervisory: the court does not conduct its own ecological assessment, but applies ordinary Wednesbury principles. Real-world in-combination effects must be addressed, although a challenge requires evidence of a likely material interaction.

The claimant campaign group sought judicial review of the Council's decision to grant hybrid planning permission for a large warehousing and employment development near Titchmarsh. The site was outside, but close to, the Upper Nene Valley Gravel Pits Special Protection Area and was treated as functionally linked land. Following an appropriate assessment under the Conservation of Habitats and Species Regulations 2017, the Council accepted a 20-hectare area at the Lilford Hall Estate as replacement land, secured by a section 106 agreement.

Five grounds challenged the classification of the replacement land as mitigation rather than compensation, alleged waste activities affecting its suitability, the treatment of the Council's Supplementary Planning Document, the assessment of in-combination effects and the adequacy of reasons. The central questions were whether the replacement land could lawfully be treated as mitigation and whether the Council had properly discharged its duties as competent authority.

1. Disposition. The application for judicial review was dismissed. Grounds 1, 3, 4 and 5 failed; permission had been granted on ground 2, but ground 2 also failed.
2. Mitigation and compensation. Under Article 6(3) of the Habitats Directive and regulation 63, preventive measures may be considered where they avoid harm or reduce it below significance. Measures that allow harm and offset it elsewhere are compensatory under Article 6(4) and regulation 64. The judge distinguished Briels v Minister van Infrastrucuur en Milieu [2014] PTSR 1120 and Grace v An Bord Pleanála (ESB Wind Developments Ltd intervening) [2019] PTSR 266, because those projects affected designated sites themselves. Their observations about forecasting future habitat did not establish that all off-site replacement functionally linked land is compensation. Here, replacement land outside the SPA could be mitigation because it was to be made suitable, secured by a section 106 agreement before development and maintained for 80 years.
3. Review and evidence. The competent authority's appropriate assessment was an evaluative judgment. Applying R (Wyatt) v Fareham Borough Council [2023] PTSR 1952, the court was not to undertake an alternative ecological assessment. Ordinary Wednesbury principles applied. Significant weight could be given to Natural England's expertise, consistently with Smyth v SSCLG [2015] EWCA Civ 174. A physical site visit was a matter of professional judgment. An assessment could rely on properly considered third-party research, as recognised in R (Chapman) v North Norfolk DC [2015] UKSC 52 and R (Wingfield) v Canterbury City Council [2019] EWHC 1974 (Admin).
4. Functionally linked land and the SPD. Functionally linked land outside a European site has no equivalent legal status to the SPA, although indirect effects are assessed within the same regulatory framework. The court explained Royal Society for the Protection of Birds v SSCLG [2014] Env. L. R. 30 accordingly. The SPD's reference to habitat creation within the SPA did not require all replacement FLL to be treated as compensation. The agreement and professional evidence supported mitigation.
5. Ground 2. The waste allegations were sufficiently evidenced for the proceedings, but expert evidence showed no material effect on the FLL. The alleged contamination did not undermine the mitigation strategy, and the section 106 obligations bound successors in title. The information was not so obviously material that its omission was unlawful.
6. In-combination effects and reasons. The Council addressed cumulative effects. Its statement that permission for Castle Manor Farm was not guaranteed was legally wrong, but the error was immaterial because the Council independently found that effective mitigation left no residual effect capable of combining with other schemes. Real-world effects had to be considered, as accepted in R (Caffyn) v Shropshire Council [2026] PTSR 104, but the claimant had to identify a likely material interaction or a reason beyond the fanciful. The reasons documents adequately explained the conclusion. In the alternative, informed by R (BUJ) v London Borough of Bromley [2026] EWCA Civ 888 and the approach in R (Lee Valley Regional Park Authority) v Epping Forest DC [2016] Env. L. R. 8, relief would have been refused under section 31 (2A) of the Senior Courts Act 1981.

not stated in the judgment.