Madzimbamuto v Lardner-Burke [1969] 1 AC 645

Facts

• The case arose after the Unilateral Declaration of Independence (UDI) by the white minority government of Southern Rhodesia (now Zimbabwe) in 1965.
• The UK Parliament rejected the UDI and enacted the Southern Rhodesia Act 1965, asserting legal authority over Southern Rhodesia.
• The appellant, Madzimbamuto, challenged the legality of the UDI and the actions of the Southern Rhodesian government, partially relying on constitutional conventions concerning UK-Southern Rhodesia relations.
• The Southern Rhodesian government's actions and claims to authority were in conflict with the UK’s legislation.

Issues

1. Whether constitutional conventions could invalidate or override the statutory authority exercised by the UK Parliament regarding Southern Rhodesia.
2. Whether the Southern Rhodesia Act 1965, a statute of the UK Parliament, had legal priority over any conflicting conventions or practices.

Decision

• The Privy Council ruled that constitutional conventions, although recognized as established political practices, are not legally enforceable by courts.
• Statutes enacted by Parliament, such as the Southern Rhodesia Act 1965, take precedence and cannot be overridden by conventions.
• The Southern Rhodesian government's actions, contrary to the statute, were not legally justified by reference to political conventions.
• The doctrine of parliamentary sovereignty was upheld, with Parliament holding supreme legislative authority.

Legal Principles

• Constitutional conventions, while politically significant, do not have legal force and are not enforceable as laws by courts.
• Parliamentary sovereignty means that Parliament can make or unmake any law, and no court or body may overrule its legislation.
• Legal challenges must be based on enforceable statutes and not solely on breaches of constitutional conventions.
• The distinction between conventions and legal rules is essential: conventions operate in the political sphere, statutes in the legal sphere.

Conclusion

The Privy Council confirmed that constitutional conventions cannot invalidate an Act of Parliament, reinforcing the supremacy of statutory law and parliamentary sovereignty in UK constitutional arrangements. The decision established a clear divide between political conventions and legally binding rules, shaping the interpretation and application of constitutional law in subsequent cases.