This essay will evaluate the effectiveness of parliamentary and judicial controls over executive power, with a specific focus on the royal prerogative. The royal prerogative, consisting of powers once held by the monarch but now largely exercised by government ministers, represents a significant source of executive authority operating outside of statute. This analysis will argue that while judicial control over the prerogative has expanded considerably, creating important checks on the executive, significant areas, particularly those concerning ‘high policy’, remain subject to limited accountability. This suggests that placing major prerogative powers on a statutory footing may be necessary to enhance democratic legitimacy.
The traditional role of the courts was limited to determining the existence and scope of a prerogative power, not how it was used. The courts can rule that a claimed prerogative does not exist, but they cannot create new ones (BBC v Johns, 1965). The primary control has long been the principle of parliamentary sovereignty, confirmed in *Attorney-General v De Keyser’s Royal Hotel Ltd* (1920). This case established that where Parliament has legislated on a matter previously governed by the prerogative, the statute takes precedence, and the prerogative power is placed in abeyance. This ensures the executive cannot use the prerogative to circumvent the will of Parliament as expressed in legislation. This principle was reinforced in *R v Secretary of State for the Home Department, ex parte Fire Brigades Union* (1995), where the House of Lords prevented the Home Secretary from using the prerogative to introduce a scheme that was contrary to an unimplemented statutory provision. These cases show the courts’ vital role in upholding the constitutional hierarchy between statute and prerogative.
A major development in judicial control came with *Council of Civil Service Unions v Minister for the Civil Service* (the *GCHQ* case) (1985). The House of Lords held that the *exercise* of a prerogative power could be subject to judicial review on the same grounds as a statutory power, such as illegality or procedural impropriety. This opened the door to greater judicial scrutiny. However, Lord Roskill noted in his judgment that some prerogative powers, by their nature, were not justiciable. These ‘excluded categories’ included matters of high policy like the making of treaties, the defence of the realm, and the dissolution of Parliament. Therefore, while *GCHQ* was a landmark step, it left a significant accountability deficit for the most politically important prerogative powers.
Recent Supreme Court judgments have challenged the boundaries of justiciability. In *R (Miller) v Secretary of State for Exiting the European Union* (2017), the court ruled that the government could not use the prerogative to trigger Article 50 of the Treaty on European Union. It reasoned that doing so would frustrate the purpose of the European Communities Act 1972 and remove statutory rights without Parliament’s consent, reaffirming the *De Keyser* principle in a modern constitutional context. Even more significantly, in *R (Miller) v The Prime Minister* and *Cherry v Advocate General for Scotland* (2019), the court held that the Prime Minister’s advice to the Queen to prorogue Parliament was justiciable and unlawful. The court reasoned that the prorogation was unlawful because it had the effect of frustrating or preventing the ability of Parliament to carry out its constitutional functions without a reasonable justification. This decision demonstrated a new judicial willingness to intervene to protect fundamental constitutional principles, even in an area previously considered to be pure politics.
Despite these judicial advances, parliamentary and judicial controls remain imperfect. For major powers like deploying armed forces or making treaties, accountability is often political rather than legal. The Ponsonby Rule, a convention requiring treaties to be laid before Parliament, was given statutory footing by the Constitutional Reform and Governance Act 2010, but Parliament can only refuse to ratify a treaty, not amend it. Similarly, the convention that Parliament should debate military action is not legally binding. These arrangements provide some political scrutiny but fall short of full democratic control.
In conclusion, the courts have become significantly more effective at controlling prerogative powers, moving from only questioning their existence to reviewing their exercise and protecting parliamentary sovereignty from their use. The *Miller* cases show a judiciary willing to enforce constitutional principles against the executive. However, gaps in democratic accountability persist, especially concerning high-policy matters like military action. Placing such powers on a statutory footing would provide a clearer legal framework and strengthen parliamentary control, aligning their use more closely with democratic principles. While this may reduce executive flexibility, the gain in accountability and legitimacy would be a worthwhile constitutional reform.
References
- Attorney-General v De Keyser’s Royal Hotel Ltd [1920] AC 508.
- BBC v Johns (Inspector of Taxes) [1965] Ch 32.
- Constitutional Reform and Governance Act 2010.
- Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374.
- R (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5.
- R (Miller) v The Prime Minister; Cherry v Advocate General for Scotland [2019] UKSC 41.
- R v Secretary of State for the Home Department, ex parte Fire Brigades Union [1995] 2 AC 513.
