The Dutch Reformed Church by 1944 opposed Boer marriage with English-speakers

Evidence

The Dutch Reformed Church has been in the forefront of the Boers’ struggle against the influence of Christian missionaries on the Cape. In 1944, however, they went one step farther and adopted “without a single voice of dissent” a motion opposing the marriage of Boers with English-speaking citizens. — Hannah Arendt, The Origins of Totalitarianism, 2323