On 3 August 1960, the National Party government announced a referendum would be held in October of that year so that voters might weigh in on the question of whether the Union of South Africa should become a republic.

The structure of the government of the Republic under the 1961 constitution was a Westminster system very similar to that of the Union under the South Africa Act 1909, except that the Queen and the appointed Governor-General were replaced by a State President elected by Parliament.

The State President was elected, for a non-renewable seven-year term, by a joint sitting of Parliament in which each Senator or member of the House of Assembly had one vote.

The State President would appoint a cabinet (formally the Executive Council) consisting of members of the Senate and the House of Assembly.

The House of Assembly was elected for a five-year term, but could be dissolved early by the State President (acting on the advice of the cabinet).

Once assented to, no court had the power to review the validity of an Act of Parliament unless it affected one of the entrenched clauses of the constitution.

[2] This clause was entrenched by the requirement that it could only be amended by an absolute majority of two-thirds of Senators and members of the House of Assembly sitting together in joint session.