A Rational Approach to Cabinet Immunity Under the Common Law

The public interest immunity (PII) doctrine empowers the government to suppress information, the disclosure of which would injure the community as a whole. However, when such information is relevant to the fair adjudication of legal rights, a tension arises between two competing aspects of the public interest: the interest of good government and the interest of justice. This tension raises questions of constitutional importance. Who should decide which aspect of the public interest must win? How should that decision be made? The aim of this article is to address these questions. In the first section, it is claimed that the courts, as opposed to the government, should have the final word on the validity of PII claims, as it would be contrary to the rule of law to prevent them from meaningfully reviewing the validity of PII claims and controlling the admissibility of evidence in legal proceedings. In addition, because of their greater independence and impartiality, judges are better placed than public officials to fairly adjudicate PII claims, especially when the government is a party to the proceedings. No classes of government secrets, not even Cabinet secrets, should be exempted from judicial review. While there is a consensus on these principles under the common law, the level of deference afforded to Cabinet immunity claims, and the way in which these claims are assessed, is not consistent in the Commonwealth. To fix this shortcoming, in the second section, it is argued that the courts should adopt a new rational approach consisting of four pillars: a narrow standard of discovery, an executive onus of justification, a cost-benefit analysis, and a judicial duty to minimize injury. The implementation of a rational approach would bolster predictability, certainty, and transparency in the judicial assessment of Cabinet immunity claims, and foster a better balance between the interests of good government and justice.