Certiorari

Section 31 of the Senior Courts Act 1981 is the statutory home of the modern remedy that replaced the old prerogative writ of certiorari. It lists 'mandatory, prohibiting or quashing orders' as the forms of relief available on an application for judicial review, and directs that any such application must be made in accordance with rules of court by the specific procedure known as an application for judicial review.

Where a quashing order is granted on the ground that a public body's decision involved an error of law, the same section gives the High Court an additional discretion: it 'may in addition' remit the matter for reconsideration or, in defined circumstances, substitute its own decision, rather than simply sending the case back to the original decision-maker with no further guidance. The remedy's old Latin name has dropped out of the statute book, but the underlying power to quash an unlawful decision of a public body is unchanged.