R v Secretary of State for the Home Department, ex parte Doody

R v Secretary of State for the Home Department, Ex parte Doody [1993] UKHL 8, [1994] 1 AC 531 was an important UK constitutional law case concerning applications for judicial review.
Facts.
Four prisoners serving mandatory life sentences requested judicial review after the Home Secretary refused to release the convicts after serving their minimum terms, but gave no reason for the decision. Under common law, there is no duty to give reason for decisions;(R(on the application of Hasan) v Secretary of State for Trade and Industry [2008] EWCA Civ 1311) however, this case is one of the exceptions.
Judgment.
Lord Mustill judged that the Home Secretary must give reasons for their decision. He argued that decisions made using a statutory power must be reached fairly, because all statutory powers are granted with the implicit assumption that they will be wielded fairly. As a result, he concluded it will often be necessary to allow a person to make representations, and therefore to allow them to know what they are responding to, they must be permitted to hear the reason they are having to make the representations at all.