Doncaster Draws the Line: Marr Solar Farm Rejected and the “Grey Belt” Myth Exposed

On 16 December 2025, Doncaster Council’s Planning Committee made a decision that matters far beyond one village and one application. The proposed Marr Solar Farm was unanimously rejected, not because councillors were hostile to renewable energy, but because they refused to accept a poorly grounded reinterpretation of planning policy.At the heart of the case was a familiar argument: that productive Green Belt land could be re-labelled as so-called “grey belt”, and that once rebranded, the normal protections no longer really applied. Doncaster said no.

A clear-eyed planning decision

The Marr proposal would have covered 77 hectares of agricultural Green Belt land for at least 40 years. Councillors were asked to accept that the public benefits renewable energy generation, business rates, and biodiversity claims “clearly outweighed” the harm.After hearing evidence, they concluded that they did not.

The committee heard objections from Marr Parish Council, local residents, and ward councillors Cynthia Ransome, Oliver Bloor, and Rachel Reed, all of whom spoke about the real-world consequences of losing productive farmland and the impact on the rural character of the area.

Independent evidence was critical. A soil assessment confirmed the land as Best and Most Versatile (Grades 2–3a), and DEFRA yield data showed the site had historically produced 40–60% above-average agricultural yields. This was not marginal or degraded land — it was high-performing farmland.

Councillors also took into account that the scheme had no viable grid connection until at least 2035, raising serious questions about deliverability and whether communities were being asked to accept permanent harm for benefits that may not materialise for a decade or more.

The “grey belt” issue and why it failed

A central plank of the developer’s case was the claim that the site should be regarded as “grey belt”. Following legal advice and late agenda amendments, council officers made an important clarification:“Grey belt” is not a statutory planning designation.

Officers acknowledged that Planning Inspectors have taken different and inconsistent approaches to the concept in appeals, and that recent decisions cited by the applicant did not override earlier findings.

Until national policy or the courts clarify the issue, it remains legally unsettled.Crucially, officers stopped presenting “grey belt” as a fact and instead made clear it was the applicant’s assertion, leaving councillors to apply the adopted Green Belt tests properly. When they did, the conclusion was straightforward: the harms were not clearly outweighed.

Renewable energy but in the right place.The developer, Enviromena, argued that the project would contribute to clean energy and energy security. Councillors accepted that energy security is a relevant consideration under national policy. But relevance does not mean dominance.Green Belt protection, high-grade agricultural land, local character, and long-term deliverability still matter.

Renewable energy policy is not a blank cheque to build anywhere.

Why this decision matters

This was not an emotional or ideological vote. It was a measured, evidence-led decision, taken with full awareness of the policy context and legal uncertainty around “grey belt”.

Doncaster’s message is clear:

Planning decisions must be based on adopted policy, objective evidence, and democratic judgement , not invented labels designed to weaken long-standing protections.As appeals are prepared and rhetoric ramps up, the Marr decision stands as a reminder that the Green Belt still means something, and that councils are entitled to say no when the planning balance does not stack up.That clarity is long overdue.