Van Zyl v Government of the Republic of South Africa

The appellants, led by Mr Josias van Zyl, were South African citizens and trusts, together with Lesotho-incorporated companies holding diamond mining interests. Swissbourgh Diamond Mines (Pty) Ltd held five mineral leases granted by the Government of Lesotho in 1988. One lease (Rampai) conflicted with the Lesotho Highlands Water Project. Lesotho authorities unlawfully cancelled and later revoked the leases in 1991–1992, actions later set aside by Lesotho courts. However, after extensive litigation, the Lesotho Court of Appeal finally held in 2000 that the Rampai lease was void ab initio for failure to obtain required consent of traditional authorities. Following this defeat, the appellants requested the Government of South Africa to afford them diplomatic protection against Lesotho, alleging unlawful expropriation, denial of justice, and corruption. The South African Government refused, stating that diplomatic protection was discretionary, involved policy considerations, and that the disputes had been adjudicated by Lesotho courts. The appellants sought judicial review and a mandamus compelling diplomatic protection. The High Court dismissed the application, and the appellants appealed to the Supreme Court of Appeal.

The appeal was dismissed. The High Court’s refusal to review the Government’s decision and to grant a mandamus compelling diplomatic protection was upheld.

This case is a leading South African authority on diplomatic protection. It clarifies that diplomatic protection is not a constitutional or common-law right but a discretionary executive function. The judgment affirms judicial restraint in matters involving foreign relations and aligns South African law with international law principles governing diplomatic protection, particularly following the Constitutional Court’s decision in Kaunda.