Legal challenge costs relating to ONR / Sizewell C nuclear site licence

• Date released: 16 January 2026
• Request number: FOI202512057
• Release of information under: FOIA

Information requested

Please provide the recorded information you hold about costs incurred by ONR in connection with the legal challenge/judicial review proceedings brought by Theberton and Eastbridge Action Group on Sizewell Ltd (TEAGS) / “Stop Sizewell C” (or any other claimant), relating to ONR’s decision to grant a nuclear site license for Sizewell C in May 2024.

In particular, please provide:

1. The total cost to ONR of dealing with the proceedings, broken down into:
   • external legal costs (solicitors, counsel, experts, disbursements/court fees),
   • internal staff costs (only where recorded/estimated in documents you hold),
   • any other material costs recorded.
2. The same costs by financial year (or other reporting period you hold).
3. Any recorded information ONR holds on cost recovery, including:
   • any costs orders in ONR’s favour,
   • any amounts recovered/receivable from another party.
4. If held, the names of any external law firms and counsel instructed and the amounts paid to each (or the most granular breakdown you already record).
5. If held, any recorded estimate/budget produced at the outset of the litigation and any post-case “lessons learned” / closure report discussing costs.

If any element is exempt (e.g. legal professional privilege), please provide the remaining non-exempt information and indicate what is being withheld and under which exemption.

Information released

I confirm that under s.1 of the FOIA, we hold some of the information you have requested, please see below for a response to each of your questions in turn.

1. The total cost to ONR of dealing with the proceedings

I confirm that the total costs to ONR to date for the challenges to ONR’s Sizewell C licence decision stands at £127,291.58. Please see below for a detailed breakdown.

TEAGS total cost to ONR - £44,256.24

Stop Sizewell C total cost to ONR - £83,035.34*

* The Stop Sizewell C total cost to ONR figure covers ONR staff costs and legal costs to date minus £10,000 awarded from the Claimant. Legal costs will not be finalised until a final meeting with the Government Legal Department at the end of January 2026, therefore this figure is estimated to increase by up to a maximum of £3,000.

2. The same costs by financial year (or other reporting period you hold).

See answer to question 1.

3. Any recorded information ONR holds on cost recovery, including:

I can confirm that we do not hold any information regarding cost recovery. The amount of £10,000 was paid directly into the Government Legal Department’s bank account from the Claimant’s solicitor.

4. If held, the names of any external law firms and counsel instructed and the amounts paid to each (or the most granular breakdown you already record).

I confirm that we instructed the Government Legal Department of 102 Petty France, London, SW1H 9GL and Rose Grogan with Flora Curtis as Junior Counsel, 39 Essex Chambers to represent ONR. See answer to question 1 for the amounts paid to each.

5. If held, any recorded estimate/budget produced at the outset of the litigation and any post-case “lessons learned” / closure report discussing costs.

I can confirm that an estimate was made for legal costs at the outset of litigation for costs up to the permission hearing and was estimated at £40,000 inclusive of VAT (£20,000 per claim to permission). 

We do not hold any further information regarding costs as a post-case “lessons learned” / closure report discussing costs was not produced.

Exemption(s) applied

None

Public Interest Test (PIT)

N/A