Learning Outcomes
After reading this article, you will be able to define prerogative powers, explain their legal basis and scope, identify their main categories, and understand their constitutional significance and limitations. You will also be able to apply the principles of judicial review to prerogative powers, including when and how courts may scrutinise their exercise, and distinguish between prerogative and statutory authority in practice.
SQE1 Syllabus
For SQE1, you are required to understand the definition and scope of prerogative powers as part of the constitutional law syllabus. In your revision, focus on:
- The definition and legal basis of prerogative powers in the UK constitution
- The main categories and examples of prerogative powers
- The relationship between prerogative powers and statutory authority
- The constitutional significance and limits of prerogative powers, including parliamentary sovereignty and the rule of law
- The circumstances in which prerogative powers are subject to judicial review
Test Your Knowledge
Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.
- What is the legal source of prerogative powers in the UK constitution?
- Can a prerogative power be exercised in an area where Parliament has legislated?
- Name two main categories of prerogative powers and give an example of each.
- Are all prerogative powers subject to judicial review? Explain your answer.
- What principle was established in Attorney General v De Keyser’s Royal Hotel Ltd [1920]?
Introduction
Prerogative powers are a core feature of the UK’s uncodified constitution. They represent the residue of discretionary authority historically exercised by the monarch, but now almost always exercised by government ministers. Understanding prerogative powers is essential for SQE1, as they illustrate the balance between executive discretion, parliamentary sovereignty, and the rule of law.
Definition and Legal Basis
Prerogative powers are legal powers recognised by the common law, not created by statute. They are the remaining discretionary powers of the Crown that have not been removed or replaced by legislation. Today, these powers are exercised by ministers on behalf of the Crown.
Key Term: prerogative powers Prerogative powers are discretionary legal powers recognised by the common law, historically exercised by the monarch, but now exercised by government ministers, in areas not regulated by statute.
The scope of prerogative powers is determined by the courts. New prerogative powers cannot be created, and existing ones cannot be extended beyond their historical limits.
Key Term: residual powers Residual powers are powers that remain with the executive where no statutory provision exists, but are lost or suspended when Parliament legislates in the same area.
Scope and Main Categories
Prerogative powers cover a range of executive functions. Their scope is limited to areas not covered by statute, and they diminish as Parliament legislates.
Foreign Affairs and Defence
- Making and ratifying treaties
- Recognition of foreign states and governments
- Deployment and command of the armed forces
- Declarations of war and peace
Domestic Governance
- Summoning, proroguing, and (historically) dissolving Parliament
- Appointment and dismissal of ministers
- Granting honours and titles
- Issuing passports
Justice and Mercy
- Granting pardons (the prerogative of mercy)
- Commuting sentences
Miscellaneous
- Granting royal charters
- Control over certain public appointments
Key Term: prerogative of mercy The power of the Crown, exercised by ministers, to grant pardons or commute sentences.
Constitutional Significance and Limitations
Prerogative powers are constitutionally significant because they allow the executive to act without specific statutory authority in certain areas. However, their use is strictly limited by key constitutional principles.
Parliamentary Sovereignty
Parliament is the supreme law-making body. If Parliament legislates in an area previously governed by prerogative, the statute takes precedence and the prerogative is suspended or extinguished.
Key Term: statutory supremacy The principle that an Act of Parliament overrides any conflicting prerogative power.
Rule of Law
The exercise of prerogative powers must comply with the law. The courts determine the existence and limits of prerogative powers, ensuring that the executive cannot act arbitrarily.
Relationship with Statute
Where Parliament has legislated, ministers must use statutory powers, not the prerogative. This was established in Attorney General v De Keyser’s Royal Hotel Ltd [1920], where the House of Lords held that statutory powers override the prerogative in the same field.
Constitutional Conventions
Some prerogative powers are limited by constitutional conventions. For example, by convention, the government seeks parliamentary approval before committing armed forces to military action, even though this is not a legal requirement.
Judicial Review of Prerogative Powers
Historically, the courts were reluctant to review the exercise of prerogative powers, considering them matters of high policy. This changed with the decision in Council of Civil Service Unions v Minister for the Civil Service [1985] (the GCHQ case), where the House of Lords held that prerogative powers can be subject to judicial review, depending on their nature.
Key Term: judicial review of prerogative The process by which courts may review the legality of the exercise of prerogative powers, applying the same grounds as for statutory powers, unless the subject matter is non-justiciable.
Not all prerogative powers are reviewable. Courts will not review powers involving national security, foreign affairs, or other matters of “high policy,” but will review prerogative decisions in areas affecting individual rights or legitimate expectations.
Worked Example 1.1
A government minister refuses to issue a passport to a citizen, relying on the prerogative power to control passports. The citizen challenges the decision in court, arguing it was made for an improper purpose.
Answer: The courts can review the exercise of the prerogative to issue passports. If the minister’s decision was made for an improper purpose or was irrational, the court may quash the decision.
Worked Example 1.2
Parliament passes an Act setting out a statutory scheme for compensation for property requisitioned during an emergency. The government tries to use the prerogative to avoid paying compensation under the statutory scheme.
Answer: The government cannot use the prerogative where Parliament has legislated. The statutory scheme takes precedence, and the government must comply with the Act.
Limits and Recent Developments
The courts have clarified the limits of prerogative powers in several recent cases:
- In R (Miller) v The Prime Minister [2019], the Supreme Court held that the Prime Minister’s advice to prorogue Parliament was justiciable and unlawful because it frustrated parliamentary sovereignty without reasonable justification.
- In R v Secretary of State for the Home Department, ex parte Fire Brigades Union [1995], the House of Lords held that the government could not use the prerogative to introduce a compensation scheme inconsistent with a statutory scheme approved by Parliament.
Key Term: justiciability The concept that some prerogative powers are subject to judicial review, while others (such as those involving national security or foreign affairs) are not.
Key Term: non-justiciable powers Prerogative powers that the courts will not review because they concern matters of high policy, such as treaty-making or defence.
Summary
| Principle | Rule |
|---|---|
| Legal basis | Prerogative powers are recognised by the common law, not created by statute. |
| Scope | Prerogative powers are residual and diminish as Parliament legislates. |
| Statutory supremacy | Statute overrides prerogative in the same field. |
| Judicial review | Prerogative powers are reviewable unless the subject matter is non-justiciable. |
| Constitutional conventions | Some prerogative powers are limited by established conventions. |
Key Point Checklist
This article has covered the following key knowledge points:
- Prerogative powers are discretionary executive powers recognised by the common law, now exercised by ministers.
- Their scope is residual and limited to areas not covered by statute.
- Statutory authority always overrides conflicting prerogative powers.
- The courts may review the exercise of prerogative powers, except where the subject matter is non-justiciable.
- Constitutional conventions and parliamentary scrutiny further limit the use of prerogative powers.
Key Terms and Concepts
- prerogative powers
- residual powers
- prerogative of mercy
- statutory supremacy
- judicial review of prerogative
- justiciability
- non-justiciable powers
