A legal letter from a campaigner has warned Surrey County Council that approval of drilling and production at the Horse Hill oil site would be unlawful.

The site, near Redhill, was stripped of its planning permission in a landmark ruling by the Supreme Court in June 2024. The court said the original permission granted in 2019 was unlawful because it failed to assess the greenhouse gas emissions resulting from the end-use of the oil.

Oil production has been suspended since October 2024.

The site operator, Horse Hill Developments Limited (HHDL), it is now seeking to reinstate the permission. If granted, this would allow the company to drill four new production wells and extract 600,000 tonnes of oil over 20 years.

Use of the oil would release about two million tonnes of greenhouse gases, HHDL has estimated in new environmental information.

Dennis May, who supported the Supreme Court case by Sarah Finch and the Weald Action Group, is the latest campaigner to oppose the application. (More details here and here)

In a letter from the law firm, Leigh Day, he argues:

• The assessment of emissions from the use of the oil was “so flawed” that permission could not lawfully be granted under the Environmental Impact Assessment (EIA) regulations.
• The proposal contravened local planning policy, including the influential development plan, because it had not demonstrated the need for more drilling and production. The plans would also have “a significant adverse effect on the climate”.
• The proposal was not supported by national policy

The letter concluded:

“The Proposed Development is contrary to Development Plan policy, will have no guaranteed benefits for national energy security, receives no national policy support, and will have a major adverse impact on the climate.

“For all of these reasons permission should be refused. A decision to grant consent, on the basis of the information currently before the Council, would be unlawful, irrational and in breach of the EIA Regulations.”

HHDL had argued in the new information that the emissions from use of the oil would be “not significant” for climate change and that drilling and production at Horse Hill would contribute to national energy security.

Mr May’s letter said there was “no credible basis for suggesting the impact on the climate would not be significant”.

HHDL’s assessment of the climate impacts was “deeply flawed”, the letter said. Methods used to give context to the significance of the emissions did not follow relevant guidance and/or were misleading, it said.

The letter added

“When the correct principles are applied it is absolutely obvious that the grant of permission for new oil and gas development … will have a major adverse effect on the climate.

“The applicant’s scattergun calculations may make it difficult to establish the precise magnitude of the effect with confidence, but it will self-evidently be significant in EIA terms. Any suggestion to the contrary is smoke and mirrors.”

“The FEI [further environmental information] submitted by HHD is logically unsound and legally inadequate. On that basis alone, permission for the proposed development should be refused.”

The letter said HHDL was wrong to argue that the application benefitted from “active national policy support” in the National Policy Statement for Energy

It said the statement did not support the argument that new oil and gas extraction should be considered as infrastructure for which there was an urgent need.

Mr May countered any argument that the application was not for new oil and gas infrastructure. He said previous lawful planning permissions at Horse Hill had been for exploration and appraisal, not production. The first permission for production had been quashed by the Supreme Court.

The revised National Planning Policy Framework (NPPF) – the blueprint for decision-making – removed the previous positive weight given to the economic benefits of onshore oil and gas development, the letter added. The NPPF also removed the requirement on decision-makers to “plan positively” for onshore oil and gas.

Date

No date has been confirmed for deciding the Horse Hill application.

But Surrey County Council told us today the January 2027 meeting of the planning committee was “currently looking the most likely”.

This meeting is expected to be on Wednesday 27 January 2027 at 10.30am. The committee usually meets in the council chamber at county council headquarters, Woodhatch Place, 11 Cockshot Hill, Reigate, Surrey, RH2 8EF.