Despite the defeat of the two Boer Republics, the South African Republic (also known as the Transvaal) and the Orange Free State, republican sentiment remained strong in the Union of South Africa among Afrikaners. D F Malan broke with the National Party of Prime Minister J. B. M. Hertzog when it merged with the South African Party of Jan Smuts to form a Gesuiwerde Nasionale Party (or "Purified National Party") which advocated a South African republic under Afrikaner control. This had the support of the secretive Afrikaner Broederbond organisation, whose chairman, L J du Plessis declared:
National culture and national welfare cannot unfold fully if the people of South Africa do not also constitutionally sever all foreign ties. After the cultural and economic needs, the Afrikaner will have to devote his attention to the constitutional needs of our people. Added to that objective must be an entirely independent genuine, Afrikaans form of government for South Africa... a form of government which through its embodiment in our own personal head of state, bone of our bone, flesh of our flesh, will inspire us to irresistible unity and strength.
In 1940, Malan, along with Hertzog, founded the Herenigde Nasionale Party (or "Reunited National Party") which pledged to fight for "a free independent republic, separated from the British Crown and Empire", and "to remove, step by step, all anomalies which hamper the fullest expression of our national freedom".
That year, a Commission appointed by the Broederbond, met to draft a constitution for a republic; this included future National Party ministers, such as Hendrik Verwoerd, Albert Hertzog and Eben Dönges.
In 1942, details of a draft republican constitution were published in Afrikaans-language newspapers Die Burger and Die Transvaler, which provided for a State President, elected by white citizens known as Burgers only, who would be "only responsible to God... for his deeds in the fulfilment of his duties", aided by a Community Council with exclusively advisory powers, while Afrikaans would be the first official language, with English as a supplemental language.