GCHQ CASE (1985) UKHL 6
Facts: Thatcher was the Prime Minister and also Minister for Civil Service at the time. The Government was concerned by the effects of industrial action (i.e. strikes) on national security. She gave orders using the prerogative powers saying that those working for GCHQ could not be part of trade unions
Issue : Was the decision to exercise prerogative power justiciable by courts? Was it lawful to prevent GCHQ employees from joining trade unions?
Held: Appeal dissmissed. While the decision was justiciable, it was reasonable to prevent British Intelligence employees from joining trade unions in the interests of national security. The House of Lords held whether or not the power was statutory or prerogative it was potentially revisable by the courts – the source of that power does not matter.
💡 This case established three grounds for judicial review: 'illegality,' 'irrationality,' and 'procedural impropriety.'