AYA & Ors, R (on the application of) v Secretary of State for the Home Department

In sample judicial review claims tried together, costs should reflect each claimant’s individual success and the issues actually litigated. A global percentage is inappropriate where it would obscure materially different outcomes, particularly where the common and individual work can be fairly allocated without undue complexity. The court may divide costs between principal components and apply an issue-based assessment within each. A claimant who succeeds on a fundamental issue may receive costs for that part despite failing on other grounds. Reasonable costs may also be awarded for successful interim relief and work undertaken before relevant decisions are withdrawn.

This was a consequential costs judgment following the substantive judgment in the five sample judicial review claims, reported at [2026] EWHC 1742 (Admin). The claims concerned amendments to the Modern Slavery: Statutory Guidance under the Modern Slavery Act 2015 and challenges to decisions affecting each claimant. The court considered whether to make a global order requiring payment of 50% of each claimant’s costs or to adopt an individualised, issue-based approach. It also determined the costs consequences of interim relief, partial success, withdrawn decisions and discrete issues that remained outstanding.

Disposition. The court rejected the proposed global order of 50% of each claimant’s costs and made individualised orders. The Secretary of State was ordered to pay 60% of KAG’s costs, 80% of EXR’s costs, 75% of GIP’s costs and 40% of HRE’s costs. AYA was awarded the costs of interim relief and reasonable costs up to withdrawal of the relevant decisions, but no further costs.

1. Costs methodology. A costs order must do justice between the parties. Broad justice may be sufficient where exact attribution of common costs would create undue complexity, but a global order was too blunt where the claimants had materially different outcomes, were represented by legal-aid practitioners and the work could be allocated without material difficulty.
2. Common and individual issues. Except for AYA, the proceedings comprised two components: the challenge to the amendment of the Modern Slavery: Statutory Guidance under s49 of the Modern Slavery Act 2015, and the individual challenges. The court allocated 50% of costs to each component and applied an issue-based approach within each. The Guidance challenge succeeded overall but failed on the Tameside point, and duplication concerns justified awarding 40% of total costs for that component.
3. Individual claims. KAG succeeded on the refusal to reconsider his trafficking claim, an important issue reflected in the order for reconsideration, but failed on his other challenges; he received 20% of the individual-claims component. EXR failed on a discrete ground and received 80% of that component. GIP succeeded on his reasonable-grounds challenge but failed on certification and received 70% of that component. HRE failed on all individual claims and received no costs for that component.
4. AYA. The court considered it likely that interim relief contributed to AYA’s removal from the relevant cohort and awarded the costs of that application. Costs reasonably incurred until the decisions were withdrawn were also recoverable. The costs of the rolled-up hearing were not reserved merely because separate issues remained outstanding; those issues were to be dealt with separately for costs purposes.

This was a first-instance consequential costs judgment following the court’s substantive judgment of 10 July 2026, reported at [2026] EWHC 1742 (Admin) . No appeal was determined.