Matthews v Ministry of Defence & Anor

Intervention in Court of Appeal proceedings is exceptional, particularly where both existing parties oppose it. A third party’s indirect interest because the decision may affect its own litigation is not, by itself, sufficient. The court should distinguish between interventions needed to present wider policy perspectives, interventions by a person with a direct interest in the outcome, and interventions based only on possible precedential effect. Where the proposed intervention is not presently justified, the court may adjourn the application so that the applicant can observe the appeal and renew the application if later developments show that its participation would assist the court or prevent injustice.

The Ministry of Defence appealed from a decision of Keith J that section 10 of the Crown Proceedings Act 1947 was incompatible with Article 6 of the European Convention on Human Rights. Claimants in a separate PTSD group action, involving similar issues concerning section 10 and the Human Rights Act, applied to intervene because the appeal might affect their claims. The parties opposed immediate intervention, but accepted an adjournment allowing the applicants to monitor the appeal and renew the application if circumstances changed.

1. Application adjourned. The proposed interveners had an indirect interest because the appeal might determine legal issues arising in their group action. That interest alone did not justify intervention.
2. Interventions in the Court of Appeal are exceptional, and are especially exceptional when opposed by both parties. The fact that other litigants may be affected by a decision on a point of law is ordinarily insufficient, since litigants in other proceedings may be bound by decisions which were not argued as fully as they might have been.
3. Three broad categories may be distinguished: intervention to provide a wider range of views on policy issues; intervention by a third party with a direct interest in the outcome; and intervention based on an indirect interest because the decision may affect other proceedings. The third category requires particular caution.
4. The applicants’ revised proposal provided a practical course. They could assist the respondent where appropriate, observe the development of the appeal, and renew the application if later developments showed that they had something material to contribute or that refusal would cause injustice. The court therefore adjourned the application without expressing a view on what future circumstances might justify intervention.
5. Costs of the intervention application were reserved. Costs incurred by the appeal parties at the hearing were reserved to the appeal hearing. The respondent was given leave to amend its notice and serve an addendum to its skeleton argument, and the appeal time estimate was increased from two to three days.

• Court of Appeal (Civil Division) — The application by PTSD group-action claimants to intervene in the Ministry of Defence’s appeal was adjourned, with costs reserved.
• Queen’s Bench Division — Keith J held that section 10 of the Crown Proceedings Act 1947 was incompatible with Article 6 of the European Convention on Human Rights and made a declaration of incompatibility. The appeal from that decision was pending.