Public interest immunity

Public Interest Immunity (PII) is a principle of English common law under which the English courts can grant a court order allowing one litigant to refrain from disclosing evidence to the other litigants where disclosure would be damaging to the public interest. This is an exception to the usual rule that all parties in litigation must disclose any evidence that is relevant to the proceedings. In making a PII order, the court has to balance the public interest in the administration of justice (which demands that relevant material is available to the parties to litigation) and the public interest in maintaining the confidentiality of certain documents whose disclosure would be damaging.

Seeking the order

An order that PII applies would usually be sought by the British government to protect official secrets, and so can be perceived as a gagging order. Where a minister believes that PII applies, he signs a PII certificate, which then allows the court to make the final decision on whether the balance of public interest was in favour of disclosure or not. Generally, a court will allow a claim of PII without inspecting the documents: only where there is some doubt will the court inspect the documents to decide whether PII applies.

Originally, a government minister was under a duty to advance a PII point where PII could be relevant, and the court took a certificate from a minister claiming PII as final and conclusive. However, over time, there has been an increase in both the ability of a minister to make a disclosure, notwithstanding the potential application of PII, and the ability of the courts to review a claim of PII. In Conway v Rimmer [1968], the House of Lords held that the courts retained the final decision on whether PII should be upheld, and, in R v Chief Constable of West Midlands, ex parte Wiley [1995], the House of Lords decided that a minister could discharge his duty by making his own judgment of where the public interest lies (that is, to disclose or to assert PII). In practice, this is thought to have led to a reduction in the number of cases when PII is asserted.

History

PII was previously known as Crown privilege, and derived from the same principle as the immunity of the Crown from prosecution before the Crown Proceedings Act 1947. However, PII is not limited to the Crown (see the NSPCC case mentioned below), and cannot be waived save in exceptional circumstances.

Infamously, a number of PII certificates were signed in relation to the prosecutions of individuals involved in the Matrix Churchill "Arms to Iraq" case, a subject that was subsequently investigated in the Scott Report.

Examples

• Duncan v. Cammel Laird and Co. Ltd [1942] AC 624. The submarine HMS Thetis sank on 1 June 1939 during sea trials with the loss of 99 lives. The families of the sailors who had been killed in the disaster claimed damages from the builders, Cammel Laird. The House of Lords upheld a certificate issued by the Admiralty claiming PII in relation to the plans of the submarine. The House of Lords also held that the courts should take a PII certificate at face value.
• Conway v Rimmer [1968]. The House of Lords held that the courts are the final arbiters of whether PII applies or not. [details to be added]
• D v. National Society for the Prevention of Cruelty to Children [1978] AC 171. The NSPCC investigated an allegation that D was mistreating her child. D claimed damages, and sought documents from the NSPCC to identify who had made the allegation. The House of Lords upheld the NSPCC's claim of PII, since its legitimate role in protecting the welfare of children was clearly in the public interest and would be threatened by disclosure.
• Air Canada v. Secretary of State for Transport [1983] 2 AC 384. A group of airlines claimed that the British Airports Authority had unlawfully increased landing fees at the instigation of a government minister. The minister disclosed some documents, but claimed PII in respect of others. The House of Lords decided not to inspect the disputed documents, holding that inspection was only required if they were "reasonably likely" to assist or damage a party's case.
• R v Chief Constable of West Midlands, ex parte Wiley [1995] 1 AC 274. The House of Lords decided that a minister could discharge his duty by making his own judgment of where the public interest lies, and was not obliged to claim PII in all cases where it may be applicable. [details to be added]
• The Scott Inquiry found that public interest immunity certificates had been issued which withheld from defense counsel certain documents which would have exonerated the defendants in the Matrix Churchill trial.
• Crown Prosecution Service v Paul Burrell [2002] - A Public Interest Immunity Certificate allowed the prosecution to apply to the judge for a ruling that disclosure of certain information would be harmful to the public interest and should not be made public.
• Crown Prosecution Service v Cornish Stannary Parliament [2002] - A Public Interest Immunity Certificate was presented to the court by the Crown Prosecution Service after about ten minutes of this hearing. A possible reason for the introduction of the PII certificate, given by the Stannary Parliament, was that the Duchy of Cornwall refuses to reveal the circumstances under which it transferred several of its properties (including Tintagel Castle) to the care of English Heritage.

European Convention on Human Rights

Article 6 of the European Convention on Human Rights protects the right to a fair trial. The European Court of Human Rights has held that Article 6 is not an absolute right and that measures restricting the rights of the defence so as to safeguard an important public interest are lawful is "strictly necessary".

External links

• Legal Guidance published by the Crown Prosecution Service on PII in criminal proceedings
• Reforming Public Interest Immunity
• The Use of Public Interest Immunity Claims in Criminal Cases