Council of Civil Service Unions and others v Minister for the Civil Service (GCHQ case)  3 All E.R. 935
Government Communications Headquarters (GCHQ) was a branch of the Civil Service, whose main functions were to ensure the security of the United Kingdom military and official communications and to provide signals intelligence for the government.
All the staff at GCHQ had a long standing right, originating when GCHQ was formed in 1947, to belong to national trade unions and most of them did so. The unions represented at GCHQ were all members of an association of Civil Service Unions and there was an established practice at GCHQ of consultation between the management and the unions about important alterations in the terms and conditions of employment of the staff.
On 7 occasions between 1979 and 1981 industrial action was taken at GCHQ, causing disruption.
On 22/12/1983, the Minister for the Civil Service issued an oral Instruction in terms of Article 4 of the Civil Service Order in Council, 1982 to the effect that the terms and condItions of Civil Servants at GCHQ would be revised to exclude membership of any trade union, other than the departmental staff association approved by the Director of GCHQ. This Instruction was issued without prior consultation with the staff at GCHQ.
The appellants applied for judicial review of the Minister’s Instruction, stating that the Minister had acted unfairly in removing their fundamental right to belong to a trade union, without consultation.
High court granted the application on the ground that the Minister ought to have consulted the staff before issuing the Instruction.
Minister appealed to the Court of Appeal and the Court of Appeal allowed it on the ground of national security.
The appellants appealed to the House of Lords. Appeal dismissed on the ground, inter alia, of national security. Once the Minister produced evidence that her decision not to consult the staff before withdrawing the right to trade union membership was taken for the reason of national security, that overrides any right to judicial review.