He was the Chairman of the Monitor Action Group party, which mainly represents conservative white Namibians, and was a member of the National Assembly of Namibia from 1990 to 2005.
[citation needed] Pretorius was a member of the all-white Legislative Assembly of South West Africa for Gobabis from 1962 to 1989.
[4] He initially represented the ACN in the National Assembly,[5] but became the chairman of a new party, Monitor Action Group (MAG), in 1991.
[6] MAG announced on 2 December 2004 that Pretorius would leave the National Assembly in March 2005 and be replaced by Jurie Viljoen.
Pretorius died on the morning of 14 July 2017 at Walvis Bay, where he has lived since retiring from active politics.