## Facts

- The case concerned AT, an appellant challenging administrative measures related to national security.
- The government relied on sensitive information it sought to withhold from AT, citing risks to national security if disclosed.
- The proceedings used the closed material procedure (CMP), whereby evidence was presented to the court and a special advocate, but not fully disclosed to AT.
- Special advocates were appointed: they were cleared to see the closed material and to represent AT’s interests in closed sessions, but were restricted from discussing the closed material with AT.
- The case was heard by the Court of Appeal, which examined whether the reliance on CMPs and the use of special advocates complied with requirements of procedural fairness.

## Issues

1. Whether the use of closed material procedures, restricting an individual’s access to evidence against them, is compatible with the principles of procedural fairness.
2. To what extent the appointment and role of special advocates can adequately safeguard the procedural rights of the individual in national security cases.
3. Whether sufficient judicial scrutiny is exercised to ensure CMPs do not disproportionately erode the right to a fair hearing.
4. Whether the government is obliged to provide the maximum possible disclosure to the individual while still protecting national security.

## Decision

- The Court of Appeal held that procedural fairness remains an essential principle, even in national security contexts.
- CMPs should only be used where their necessity and proportionality are established in light of the risks posed by full disclosure.
- The essential role of special advocates was affirmed, though the court acknowledged built-in limitations, particularly regarding the inability to communicate closed material to the appellant.
- The court emphasized the duty to provide the affected individual with as much information as feasibly possible, through redacted or summarized material.
- Rigorous judicial scrutiny was required in CMP cases to ensure the balance between national security and fairness.
- The judgment has influenced subsequent jurisprudence and procedures surrounding CMPs.

## Legal Principles

- Procedural fairness is a fundamental requirement in administrative legal proceedings, including national security cases.
- Closed material procedures are only justified when strictly necessary and proportionate to national security needs.
- The role of special advocates is essential to safeguarding the individual's interests, but judicial oversight must compensate for their communication restrictions.
- The state is required to disclose as much information as possible to the affected person, even if in redacted or summarized form.
- Courts must ensure that CMPs do not unduly limit rights to a fair hearing and that robust safeguards are in place.

## Conclusion

AT v Home Secretary [2012] EWCA Civ 42 clarified the procedures and safeguards required when closed material procedures are used in national security cases, reaffirming that procedural fairness and effective judicial scrutiny are essential even in the context of sensitive government interests. The judgment established enduring principles balancing the need for security with the right to a fair hearing, influencing subsequent law and practice.
