Public interest immunity

The purpose of the hearing that is due to begin in the Criminal Appeal Court on Tuesday, 27 May is to decide whether to uphold or reject the United Kingdom Government’s assertion of public interest immunity (PII) in respect of a document, emanating from a foreign country (not the United States of America), that the Scottish Criminal Cases Review Commission regarded as of such significance that the Crown’s failure to disclose it at the Lockerbie trial may have given rise to a miscarriage of justice.

As a distinguished Scottish judge said in 1968 in a case in the House of Lords: “It is universally recognised that there are two kinds of public interest which may clash. There is the public interest that harm shall not be done to the nation or the public service by disclosure of certain documents, and there is the public interest that the administration of justice shall not be frustrated by the withholding of documents which must be produced if justice is to be done.”

What the court has to do is to assess the harm, if any, that would be done to the national interest through disclosure, and weigh that against the harm that would be done to the administration of justice (eg the likelihood, or the possibility, that an unjustified conviction might be upheld) if disclosure were denied. In this balancing exercise, the court must consider what aspects of the UK’s national interest would be harmed by disclosure (eg national security; relations with friendly foreign governments) and what the extent and gravity of that harm would be. Before the Government’s PII claim can succeed, this potential harm must outweigh the public interest in (and the European Convention on Human Rights requirement of) the fairness of criminal proceedings, which involves an accused person’s having access to all relevant material that might assist his defence.

In the past, PII claims have been relatively frequently been upheld in civil cases, but only rarely upheld in criminal cases, where the liberty of the accused person is at stake. And given that the document in question was already in the hands of the Crown at the time of the Lockerbie trial in 2000, I suspect that the court will take some convincing that serious harm would be done to the UK’s national interest by its disclosure today, some eight years later.