UPOW (a postal trade union) decided not to deliver mail to SA so as to put pressure on Apartheid and a private individual, Mr Gouriet, thinking that such an action was against the public interest, asked the attorney general to be a plaintiff against UPOW. AG refused. Gouriet then sought (1) an injunction against the action by UPOW and (2) a court declaration that the AG had acted outside of his duty. HL said that the AG alone could bring actions in “the public interest” so that Mr Gouriet had no power to get an injunction ordered against UPOW, while the AG’s discretion as to whether or not to act as plaintiff was his alone and NOT reviewable by the courts.