The 1958 South African general election, held on 16 April of that year, led to a victory for the National Party, under the leadership of J.G. Strijdom, which took 103 seats in the House of Assembly. It was the first election in South Africa with a whites-only electorate, following the removal of the Cape Qualified Franchise in the late 1950s to be replaced by four MPs elected to represent Coloured voters in separate constituencies.
Changes in composition and franchise
Native Representative Members
The third term of the elected to represent black voters, from special electoral districts in Cape Province under the Representation of Natives Act 1936, expired on 30 June 1954. These seats were not vacated by a dissolution of Parliament, so they were not contested at the 1953 general election. The three representative seats were filled by elections on 1 December 1954. Two Liberal Party of South Africa MPs were returned. Stanford took his seat from an Independent. Ballinger had been elected as an Independent at the three previous representative elections, before becoming the first President of the Liberal Party, when it was formed on 9 May 1953. The third seat was taken by L.B. Lee-Warden, an Independent candidate. The term of these members expired on 30 June 1960. The Native Representative Members seats were to be abolished in 1960, at the end of the current term.
Coloured Representative Members
The Separate Representation of Voters Act 1951, had provided for coloured voters in Cape Province to be removed from the general voters rolls and placed on a separate roll. The coloured voters lost the right to participate in general roll elections and were given four representative members in Parliament. The implementation of the 1951 Act was delayed in what is known as the Coloured vote constitutional crisis, due to legal arguments about whether Parliament had complied with the requirement for a two-thirds majority in joint session, before it could remove the coloured voters from the general roll. Eventually legislation to change the size and electoral system for the Senate was enacted, which the courts accepted as enabling the 1951 Act to be validated by the constitutionally required margin. The Coloured Representative Members were elected, for the first time, on 3 April 1958, for a term expiring with the next dissolution of Parliament. Four supporters of the United Party were elected to fill the new seats.
Delimitation of electoral divisions
The South Africa Act 1909 had provided for a delimitation commission to define the boundaries for each electoral division, for general roll voters in the four provinces. The representation by province, under the eleventh delimitation report of 1958, is set out in the table below. The figures in brackets are the number of electoral divisions in the previous delimitation. If there is no figure in brackets then the number was unchanged.
At the end of the 11th Union Parliament, when it was dissolved in 1958, the House of Assembly consisted of two types of members. White voters were represented by 156 members and black voters in Cape Province by three white MPs. A third type of MP was about to be elected, so that four white MPs would represent coloured voters in Cape Province. They were known as the Coloured Representative Members. The general election, on 16 April 1958, only affected the representatives of white voters. The other members were elected on different dates. The representation by party and province, at the dissolution was:-
The general election, for 156 seats in the 12th Union Parliament, was the first in South African history when only voters classified as white took part. In the eleven previous general elections, the Cape Province and Natal general electoral roll had included some black, Asian and coloured electors. The vote totals in the table below may not give a complete picture of the balance of political opinion, because of unopposed elections and because contested seats may not have been fought by a candidate from all major parties. The total registered electorate was 1,563,426. The votes cast were 1,162,576. The election saw the collapse of the South African Labour Party which lost all 5 of its seats and whose vote dropped from almost 35,000 votes in 1953 to 2,670 votes in 1958. The drop in support is largely attributed to the party leader Alex Hepple's growing outspokenness in opposition to apartheid and his co-operation with the African National Congress, positions which were not supported at the time by white workers who were the bulk of the Labour Party's electorate. The overall composition of the House, after the general election, was as below. There were boundary changes, from the delimitation of seats in the previous Parliament, so no attempt is made to identify changes.