After the National Party of J.B.M. Hertzog merged with the South African Party of General Jan Smuts and formed the United Party (UP) during the World Economic Crisis in 1932, Strijdom was part of the break-away faction of the National Party, named the "Gesuiwerde Nasionale Party" (Purified National Party). Later, after the United Party was formed, the GNP became known as the (Reunited) National Party under the leadership of Dr. D. F. Malan. Malan, Strijdom and their followers distrusted Smuts and opposed his pro-British policy. Most of the National Party's MPs stayed with Hertzog, and as Strijdom was loyal to Malan, he was the only MP from Transvaal to support Malan's ideals.