Royal Prerogative in UK Law

So far as individuals are concerned, it is res inter alios acta from which they cannot derive rights and by which they cannot be deprived of rights or subjected to obligations; and it is outside the purview of the court not only because it is made in the conduct of foreign relations, which are a prerogative of the Crown, but also because, as a source of rights and obligations, it is irrelevant.

The prerogative powers of the Crown remain in existence to the extent that Parliament has not expressly or by implication extinguished them. But under the principle in Attorney-General v. De Keyser's Royal Hotel Ltd. [1920] A.C. 508, if Parliament has conferred on the executive statutory powers to do a particular act, that act can only thereafter be done under the statutory powers so conferred: any pre-existing prerogative power to do the same act is pro tanto excluded.

Like my noble and learned friend Lord Diplock, I believe that the law relating to judicial review has now reached the stage where it can be said with confidence that, if the subject matter in respect of which prerogative power is exercised is justiciable, that is to say if it is a matter upon which the court can adjudicate, the exercise of the power is subject to review in accordance with the principles developed in respect of the review of the exercise of statutory power.

The question is simply whether the nature and subject matter of the decision is amenable to the judicial process. Looked at in this way there must be cases in which the exercise of the Royal prerogative is reviewable in our judgment. If, for example, it was clear that the Home Secretary had refused to pardon someone solely on the grounds of their sex, race or religion, the courts would be expected to interfere and in our judgment would be entitled to do so.

In 1611 when the King, as the executive government, sought to govern by making proclamations, Sir Edward Coke declared that: "The King hath no prerogative but that which the law of the land allows him": see the Case of Proclamations (1611) 12 Coke's Reports at page 76.

by statute, the Executive no longer derives its authority from the Royal Prerogative of the Crown but from Parliament, and that in exercising such authority the Executive is bound to observe the restrictions which Parliament has imposed in favour of the subject.

What, then, do we mean by the prerogative in this connection? I say "this connection" because in our history the prerogatives of the Crown have been many and various, and it would not be possible to embrace them under a single description.