House of Lords · Unanimous; Lords Fraser, Scarman, Diplock, Roskill and Brightman
Facts
Staff at the Government Communications Headquarters had long been allowed to belong to trade unions, and changes to conditions of service had been made after consultation. In January 1984 the Minister for the Civil Service, acting under the prerogative as embodied in an Order in Council, instructed that staff should no longer be allowed to belong to national trade unions, without prior consultation. The unions and individual employees challenged the instruction.
History
At first instance, Glidewell J granted a declaration that the instruction was invalid for failure to consult. The Court of Appeal allowed the appeal of the Crown. The unions appealed to the House of Lords.
Issue
Whether a decision made under a prerogative power was open to judicial review, whether the unions had a legitimate expectation to be consulted before the change, and whether national security considerations justified the failure to consult.
Held
Appeal dismissed. The decision was in principle subject to review, and the unions had a legitimate expectation of consultation, but that expectation was outweighed by the interests of national security, on which the court deferred to the evidence of the Crown.
Ratio
- The fact that a power derives from the prerogative and not statute does not remove a decision from judicial review; what matters is the subject matter of the power and whether it is suitable for review by a court.
- A legitimate expectation that a person will be consulted before a change can arise from a regular practice of consultation, and a failure to consult can be unlawful for procedural impropriety unless there is good reason.
- National security can justify a departure from fair procedure, the question whether national security requires it being one on which the evidence of the government must be accepted unless there is some reason to doubt it.
The judgments
Lord Fraser of Tullybelton (concurring)
He held that the unions had a legitimate expectation of consultation, but that the Minister had shown that consultation would have risked industrial action that threatened national security, so the instruction stood.
Lord Scarman (concurring)
He held that the source of a power in the prerogative or statute did not decide whether it was reviewable, and that the question was the subject matter, and he accepted the case on national security.
Lord Diplock (concurring)
He stated the grounds of judicial review as illegality, irrationality and procedural impropriety, with the possibility of proportionality in future, and found that national security was a matter for the executive.
Lord Roskill (concurring)
He considered that some prerogative powers by their nature are not susceptible to review, such as the making of treaties, the defence of the realm, the prerogative of mercy, the grant of honours, the dissolution of Parliament and the appointment of ministers.
Lord Brightman (concurring)
He agreed that the claim failed because the evidence on national security was a sufficient justification for the absence of consultation.
Key reasoning
- The reviewability of a power depends on whether it affects the rights or legitimate expectations of the individual and whether its subject matter is justiciable, not on the label of the power.
- Past practice of consultation created an expectation that the unions would be consulted, which the government did not dispute.
- The court accepted the evidence presented on behalf of the Minister that prior consultation would itself have prompted disruption at GCHQ, and national security was a matter for the executive to judge.
Obiter
- Lord Diplock identified three heads of review, illegality, irrationality and procedural impropriety, and suggested that proportionality might be adopted in future, an analysis which has been widely used as the classification of the grounds of judicial review.
- Lord Roskill listed categories of prerogative power which in his view were not suitable for review, including treaties, defence, honours, mercy, dissolution of Parliament and the appointment of ministers.
Where it fits in the module
In the study of the Crown and the royal prerogative, the case fixes the modern approach to control of executive power by courts. It tests how far the courts will examine decisions of the government under the prerogative and the extent to which national security, a ground on which the courts defer, limits review.
Criticisms
- The deference shown to the assertion of national security meant that the court treated an executive statement as conclusive without testing the claim, which weakens the supposed availability of review in the most sensitive areas.
- The suggested list of non-justiciable prerogative powers rests on the nature of the subject matter in a way that is uncertain, and later courts have not applied it as a closed list.
- The decision confirms review of the prerogative but leaves unclear the grounds for deciding which executive actions are too political for the courts, which can be seen as leaving the boundary to the discretion of judges.
Written with AI (claude-sonnet-5.5 (Claude Code writer)) on 1 November 2026, reviewed for errors by a second model (claude-sonnet-5.5 (Claude Code checker)). Read the case itself at [1984] 3 All ER 935. Spotted an error? Tell us.