In Chapter 2 we examined the sources of constitutional rules within the UK’s governance order. We established the importance of Acts of Parliament, which can be used to override other rules and have not, in the UK’s history as a state, been challenged by the courts. The theoretical relationship between constitutional sources, however, provides a distorted picture of the workings of the UK Constitution, and this section therefore explores the workings of the institutions of central government in the UK. This chapter concentrates upon the executive branch of government and how this branch has achieved a dominant position within the UK Constitution, both in spite of and because of parliamentary sovereignty. We begin by charting how the modern executive managed to accrue powers shed by a declining monarchy and proceed to analyse how the politicised elements of the executive branch were able to harness the party system and support of the civil service to exert control over Parliament.

This chapter examines the role, powers and effectiveness of the Parliamentary Commissioner for Administration, an officer of Parliament more frequently referred to as the Parliamentary Ombudsman. The Parliamentary Ombudsman plays an important role in helping to secure governmental accountability and also encourages continuing improvement in the standards of administrative decision-making. Alongside an assessment of the role, jurisdiction and powers of the Ombudsman, this chapter considers the effectiveness of the office and possibilities for reform.

In most countries a codified constitution explains the overarching relationship between individuals and the state and establishes a coherent hierarchy of authoritative sources of law. The absence of a codified UK Constitution means that constitutionally significant rules can be found in a range of legal sources including statutes, statutory instruments, the Royal Prerogative and judicial decisions. There is even a prominent role for political understandings, known as conventions. This chapter compares the operation of the UK Constitution to the codified constitutions adopted in most other liberal democracies and introduces constitutional debates which will be developed in later chapters.

In this chapter we examine the structural reforms to the apex of the judicial branch implemented as a result of the Constitutional Reform Act 2005. By reforming the office of Lord Chancellor and establishing a Supreme Court for the UK, the Constitutional Reform Act severed the structural link between the executive, legislature and the senior judiciary in the UK. As a result, the Act has arguably cemented the idea of the institutional independence of the judiciary and has shown the contemporary relevance of ideas associated with separation of powers in achieving and implementing constitutional renewal.

The UK’s Constitution is not insulated from external influences. In considering the sources of constitutional law, we cannot ignore the influence of public international law and international legal orders to which the UK belongs. This chapter therefore examines the relationship between the UK’s legal systems, public international law in general, and introduces specific treaties which are significant for the UK’s legal systems, such as the European Convention of Human Rights (ECHR).

The constitutional doctrine of separation of powers seeks to divide governmental power between three arms, or branches, of government – the legislative, executive and judicial branches – with the aims of preventing arbitrary or oppressive government, and of promoting efficiency in the operation of government. Separation of powers has historically played an uncertain role in the constitution of the United Kingdom as it is argued to be incompatible with the doctrine of parliamentary sovereignty. This chapter will examine how far the UK Constitution can be said to reflect a separation between governmental institutions and their functions, and how far the values of separation of powers can be seen in our constitutional arrangements.

This first part of this chapter examines what is meant by the term ‘human rights’ and the role of this concept in twenty-first century public law. The concept of human rights is intended to protect those civil, political, social and economic interests vital to maintaining human autonomy. Human rights law, in its modern guise, came to the forefront of public thought across Europe in the aftermath of the Second World War, an era which produced the European Convention on Human Rights (ECHR). The institutions established by the ECHR and the rights enumerated therein continue to evolve, providing the basis for some of the UK’s commitments in international law. The ECHR regime is designed to provide a framework not only for protecting human rights but, where necessary, for balancing competing rights against each other and against other important societal interests. The concept of human rights therefore provides a basis both for enumerating the most fundamental interests enjoyed by individuals within the UK and for restraining the actions of public authorities which conflict with those interests.

This chapter examines the doctrine of parliamentary sovereignty, the commonly used shorthand for the legal supremacy attributed to Acts of Parliament within the hierarchy of norms in the UK’s constitutional system. The characteristics of the doctrine are examined, alongside its historical origins and the crucial distinction between the idea of legal sovereignty and that of political or popular sovereignty. We then go on to examine potential limitations on Parliament’s legislative power, before examining and assessing contemporary challenges to the orthodox model of legal sovereignty. While the doctrine of legal sovereignty undoubtedly forms the backbone of the UK’s Constitution, it should be considered alongside the principle of the rule of law and – to a lesser extent – that of separation of powers. Parliamentary sovereignty is also closely aligned with the idea of political accountability. Each of these additional constitutional principles is considered in the chapters which follow.

In the last chapter, we saw that judicial review is not the same as an appeal against a lower court’s decision. The courts will only intervene in the operation of a public function on the basis of particular criteria. The longest-established and least controversial of these criteria is illegality, which primarily involves the courts checking that lawful authority exists for a decision maker’s actions (fundamental to even the most limited conceptions of the rule of law). The courts, however, have developed further grounds for judicial review beyond this core function. Even if a public body has lawful authority for an action, the courts may still scrutinise its activity on the basis that there was no rational basis for the action (controversially requiring the courts to consider the reasoning behind a decision) or on the basis that adequate procedural safeguards were not operative within the decision-making process (which can, equally controversially, involve the courts introducing procedural requirements upon exercises of a power beyond those imposed by Parliament). In recent decades judicial review has been further extended to protect the interests of claimants who received specific promises from a decision maker, preventing that public body from reneging upon those promises without good reason.

Parliament is the dominant legal force in the constitution of the United Kingdom. The Parliament of the United Kingdom, situated at Westminster, is also the hub of the United Kingdom’s political system. Our system, therefore, is one of parliamentary – not constitutional – government. But government in the United Kingdom is largely conducted through rather than by Parliament. Behind the idea of parliamentary government lie two important features of the United Kingdom’s legislature and therefore of the constitution itself: the pre-eminence within Parliament of the House of Commons and the dominance of the House of Commons by the government of the day. This chapter examines both features, in the context of the role, functions and composition of the House of Commons.

For nearly half a century the UK’s Constitution was part of the most globally significant supranational legal order. The UK, like other member states, granted the European Union (EU), or shared with it, competences over entire areas of law making, in order to secure the benefits of harmonisation of rules across the member states. Such deep cooperative commitments within this supranational order are maintained by binding rules, and throughout its membership UK policy makers struggled to reconcile to this loss of freedom of action. After the UK joined the European Economic Area (EEA), a nationwide referendum was held which approved this decision. Over four decades later, amid growing discontent within the Conservative Party over the UK’s EU membership, David Cameron as Prime Minister renegotiated the terms of the UK’s membership and called a referendum on whether the UK should remain part of the EU based on these terms. In June 2016, a majority of referendum voters voted to leave the EU. This chapter explores what the EU is, the consequences of the UK’s membership of the EU for its constitutional order between 1973 and 2020, the process of the withdrawal from the EU and the post-Brexit relationship between these orders.

This chapter explores the impact of devolution upon particular aspects of the UK’s constitutional arrangements. First, devolution required a major departure for the courts from their historic reluctance to review legislation. Devolution obliges the courts to become involved in politically contentious debates and, where necessary, to strike down legislation enacted by the devolved legislatures if it exceeds their competences under the devolution arrangements. As the devolved administrations push for increased autonomy, this may even require the courts to rule upon the legitimacy of legislation seeking independence. The chapter thereafter considers the place of England within the Union following devolution to the other constituent parts of the UK. England remains the only non-devolved territory within the UK and, as such, continues to be governed from Westminster. This gives rise to a number of representational, legislative and administrative difficulties. This chapter outlines the consequences of England lacking any meaningful devolved structures of government, and the proposed responses to the difficulties associated with this most obvious of devolution’s asymmetries.