Council of Civil Service Unions v Minister for the Civil Service (GCHQ) is a British intelligence agency that provides signals intelligence to the British government and armed forces. Prior to 1983 its existence was not acknowledged, despite the fact that it openly recruited graduates. Following a spy scandal in 1983, the organisation became known to the public, and the government of Margaret Thatcher decided a year later that employees would not be allowed to join a trade union for national security reasons. The Minister for the Civil Service is a position held "ex officio" by the Prime Minister. This was done through an Order in Council, an exercise of the Royal
Council of Civil Service Unions v Minister for the Civil Service the determination of national security issues is an executive function and it would be inappropriate for the courts to intervene. The House of Lords held the Royal Prerogative was subject to judicial review, just like statutory instruments. However, on national security grounds, the action of restricting the trade union was justified. Lords Fraser, Scarman and Diplock all believed that the issue of national security was outside the remit of the courts. Lord Diplock wrote "it is par excellence a non-justiciable question. The judicial process is totally inept to deal with the sort of problems which it involves." Lord Fraser stated