21. Public policy

Abstract

The public interest in efficient and fair trials may be seen as underlying the rules of disclosure in civil litigation, whereby a litigant is obliged to make pre-trial disclosure of the documents on which he relies and the documents that adversely affect his own case or adversely affect, or support, another party’s case, even though such documents may not be admissible evidence at the trial. There is also a public interest in enabling material to be withheld where its production would harm the nation or the public service. Where these two kinds of public interest clash and the latter prevails over the former, relevant and otherwise admissible evidence is excluded at trial. Such material is said to be withheld by reason of ‘public interest immunity’. This chapter discusses the development of the modern law on public interest immunity; the scope of exclusion on grounds of public policy; and related procedural issues in civil and criminal cases.