This chapter reviews the modern cases on the ‘third source’ in England and Wales and around the Commonwealth. This review illustrates that the law is fundamentally uncertain on the legal nature and exact provenance of these powers within each jurisdiction surveyed. It also illustrates that basic questions of legal theory relating to official empowerment and official action are unavoidable in the context of non-statutory executive powers. This demonstrates the gap between theory and practice in a specific context and justifies the need for the basic and wide-ranging interrogation of the law of judicial review undertaken in the book.

This chapter presents a concept of office as the central, organising concept in public law. Public law is, effectively, the law of public offices. An office is a stable, institutionalised social role tantamount to an artificial legal person that is occupied by a person from time to time in virtue of which that person acts ‘outside themselves’ and for the political community as a whole. This is the key to understanding the law of judicial review, which is uniquely concerned with this official mode of action. The concept of office has languished at the margins of public law theory since the nineteenth century reform of the English civil service. Its reinstatement is essential to understand the judicial review of official action beyond statute, and would reinvigorate and enrich public law theory more broadly as well – up to and including the foundation of a powerful conception of the rule of law.

This chapter sets out the taxonomy of non-statutory executive powers ultimately adopted. It is a very simple taxonomy that draws a fundamental distinction between statutory and non-statutory executive powers but no distinctions for the purposes of judicial review between non-statutory executive powers associated with the Royal Prerogative and those that are more mundane, and appear to be nothing more than the ‘residual liberties’ of the Crown as a legal person. Once the logic of office, official empowerment, and official action is adopted as a premise, the idea of the ‘third source’ as generally articulated simply falls away. While the distinction may be interesting or useful in a historical sense, it is of no relevance to the ‘how’ or ‘why’ of judicial review.

This chapter introduces the problem of official action beyond statute as a central concern to public law theory. It reviews the most important classical accounts of the Royal Prerogative and the modern notion of a ‘third source’ of executive power besides statute and prerogative. It also introduces a major them in the book, namely the concept of ‘official power’ as a set of ‘legal powers’ and uses this critically to assess common misconceptions about the nature of official action beyond statute – particularly conceptions of the third source as a set of ‘residual liberties’ inuring in the Crown in common with private individuals.

This chapter provides an account of the Crown and its officials (and the relationship between them). This is the first of three chapters that provide fundamental building blocks for the judicial review of non-statutory executive powers. The Crown is an ambiguous term, which can specify the Queen, HM Government, and even the organised political community ('commonwealth') as a whole. Working through these ambiguities is essential in order to describe who is being reviewed (and why), and this entails working through some long-standing questions about the Crown's legal personality and relation to the person who is Monarch. Rejecting the idea that the Crown is a natural person (ostensibly because the Queen is a natural person) is the first step that leads, logically, to a theory of judicial review via a theory of office,official empowerment, and action in an official capacity.

This chapter present my own theory of judicial review, which I call a ‘common law ultra vires theory'. Based around the logic of ‘acting beyond one's powers', judicial review follows the narrow and broad limb. Although statutory provisions will be relevant and even dispositive where they exist, both of these limbs have roots in the common law supervisory jurisdiction of the judicial office to interpret and enforce the rules of competence and rules of conduct that empower and constrain executive officials. This theory of judicial review applies naturally and without distortion to statutory and non-statutory executive powers alike, and, within the latter category, no further distinctions need to be made between those powers associated with the Royal Prerogative and those that follow as a logical consequence of the Crown being a corporation with legal personality – or indeed any other basis of executive vires. Looking at recent UK Supreme Court jurisprudence for indirect but significant support, I argue that ‘justiciability'and ‘deference’ have a more limited role to play in the theory and practice of judicial review than first appears – even in the context of the ‘high’ prerogatives.