public law Cases

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Council of Civil Service Unions v Minister for the Civil Service (The GCHQ case) [1985] AC 374, [1985] ICR 14

Public Law – Prerogative Power – Unions – National Security – Civil Service - Judicial Review – Lord Diplock – Lord Roskill


In the 1980’s, with the United Kingdom under the Conservative government led by Margaret Thatcher, it was ruled that any and all employees of the Government Communications Headquarters (GCHQ) were prohibited from joining any trade union. This decision was justified based on the potential threat to national security, and enforced using an Order of Council which is an exercise of the Royal Prerogative Power.


By limiting access, or completely refusing access to trade unions to employees, certain individuals affected were not able to rely on certain employment legislative provisions or be represented by a Union.

History of the case

The court case was raised by the Council of Civil Service Unions, bringing the matter to court via judicial review. At first instance the case was heard at the High Court of Justice, where it was ruled that the Order was invalid, however this was overturned on Appeal at the Court of Appeal. There is was held that the consideration of national security was of paramount importance, and as such considerations and decisions made on this basis were not to be considered.

The case was now heard on appeal at the House of Lords: the ruling of the house was that exercising of the Royal Prerogative were capable of being subject to judicial review. This ruling marked a massive departure from the law previous, however the Lords did hold that on issues of national security, this right was exempt.


The importance of the case is found in the departure from the unwillingness of the courts to judicially review prerogative powers. Lord Diplock found that where a person’s ‘private rights or legitimate expectations’ are effected by the execution of the prerogative power, then that execution of power should be amenable to review. Lord Fraser and Lord Brightman came to the same conclusion based on the view that where the prerogative power was delegated from the monarch, the exercise of that power could be reviewed via judicial review. Lord Roskill stated:

“If the executive instead of acting under a statutory power acts under a prerogative power and in particular a prerogative power delegated to the respondent under article 4 of the Order in Council of 1982, so as to affect the rights of the citizen, I am unable to see, subject to what I shall say later, that there is any logical reason why the fact that the source of the power is the prerogative and not statute should today deprive the citizen of that right of challenge to the manner of its exercise which he would possess were the source of the power statutory.”

Following the GCHQ case, it was found that prerogative powers (bar for national security reasons) can be judicially reviewed for legality

This case has been cited in the following case:

R (Bancoult) v Secretary of State for Foreign and Commonwealth Affairs (No 2) [2008] UKHL 61