## 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.

Madzimbamuto v Lardner-Burke [1969] 1 AC 645