Limitation of the Royal Prerogative by Act of Parliament
The Bill of Rights 1689 settled that the prerogative could be restricted by Act of Parliament, by declaring that some prerogatives, which the Crown had formerly claimed, did not exist.
Occasionally cases still arise where Parliament confers powers which are similar to, or which overlap with existing prerogative powers, and the courts therefore have to decide how the two inter-relate. In principle, because of parliamentary supremacy, the statute prevails in the event of conflict, but whether there is a conflict depends on the interpretation of the Act. The possibilities are as follows:
• the Act abolishes the prerogative power
• the Act temporarily suspends the prerogative power
• the Act supplements the prerogative power, but leaves it intact.
Prerogative and statute
Consider Attorney-General v. De Keyser’s Royal Hotel Ltd  AC 508 and R v. Secretary of State for the HomeDepartment, ex parte the Fire Brigades Union  2 AC 513. Try to focus on how each case deals with the relationship between the prerogative and statute, and consider the following question. [You should be able to answer this question by exploring the discussion in the textbook or the case headnotes, rather than reading the judgments in full.] In each case a statutory power overlapped a prerogative power. Into which of the categories referred to above did each case fall, and why?
Note also that R v. Secretary of State for the Home Department, ex parte Northumbria Police
Authority  QB 26 provides a (rare) example of a statute supplementing the prerogative power. The Court of Appeal decided in this case that Parliament did not intend that the police authority should have an exclusive power to supply CS gas, so the Home Secretary could lawfully do so either in exercise of the ancient prerogative power to maintain law and order or under statutory powers in the Police Act 1964. This decision has been criticised (see, for example, Ewing and Gearty, Freedom Under Thatcher (Clarendon Press, 1990)) not least for the apparent lack of legal authority cited in favour of the existence of the prerogative power referred to.
Judicial review of the exercise of prerogative powers
We have seen that it was clearly established in the seventeenth century that the Royal
Prerogative was limited by law. However, it is only in relatively recent times that the courts have been prepared to review the manner in which a prerogative power was exercised by the executive. The law in this area was significantly advanced by decision of the House of Lords in Council of
Civil Service Unions v. Minister for the Civil Service  AC 374 (‘the GCHQ case’), with the result that the exercise of some prerogative powers was held to be subject to judicial review.
You may recall that judicial review is a procedure which enables thecourts to decide whether government acts are lawful. The courts are in effect subjecting the exercise of certain prerogative powers to the same principles of administrative law as they would use to review the exercise of statutory powers by the executive. The next question invites you to analyse the GCHQ case.
Review of the Royal Prerogative
Consider Council of Civil Service Unions v. Minister for the Civil Service and the following questions:
1 Why did their Lordships think that acts under the prerogative should be subject to judicial review? (You may find the the speeches of Lord Scarman and Lord Roskill the clearest on this point.)
2 Did their Lordships think that all acts of the Crown under the prerogative should be subject to judicial review? Give some examples of areas which would not be subject to review.
3 Why did their Lordships refuse to hold that the government had unfairly withdrawn the right to trade union representation at GCHQ?
4 Does the decision give effect to the principle of the rule of law?
5 Is there any justification for the decision in terms of…