▁in ▁World ▁War ▁II . ▁ ▁In ▁ 1 9 3 2 ▁he ▁was ▁noted ▁for ▁playing ▁two ▁first - class ▁cr icket ▁matches ▁for ▁Western ▁Province . ▁ ▁His ▁young est ▁brother ▁was ▁Johannes ▁de ▁Vill iers ▁Gra aff , ▁a ▁noted ▁South ▁African ▁W elf are ▁Econom ist . ▁ ▁Political ▁career ▁ ▁Gra aff ▁became ▁a ▁member ▁of ▁the ▁House ▁of ▁Assembly , ▁the ▁lower ▁house ▁of ▁Parliament , ▁in ▁ 1 9 4 8 , ▁the ▁year ▁his ▁United ▁Party ▁was ▁ou sted ▁from ▁government ▁by ▁the ▁conserv ative ▁National ▁Party , ▁which ▁promised ▁to ▁en act ▁a ▁de ▁j ure ▁system ▁of ▁apart heid . ▁Vict ory ▁in ▁De ▁Vill iers ' ▁constitu ency ▁( H ott ent ots - Hol land ) ▁was ▁the ▁only ▁UP ▁pick up ▁in ▁the ▁election ; ▁never theless , ▁Gra aff ▁took ▁over ▁leadership ▁of ▁the ▁United ▁Party ▁in ▁ 1 9 5 6 ▁from ▁J . G . N . ▁Stra uss . ▁He ▁led ▁the ▁opposition ▁to ▁the ▁govern ments ▁of ▁three ▁apart heid ▁prime ▁minister s , ▁Johannes ▁St rij dom , ▁Hend rik ▁Ver wo erd , ▁and ▁B . J . ▁Vor ster . ▁ ▁He ▁led ▁the ▁opposition ▁to ▁a ▁republic ▁in ▁the ▁ 1 9 6 0 ▁refer endum , ▁and ▁stated ▁that ▁South ▁Africa ' s ▁membership ▁of ▁the ▁Commonwealth ▁was ▁under ▁threat , ▁and ▁the ▁declaration ▁of ▁a ▁republic ▁would ▁lead ▁to ▁South ▁Africa ▁being ▁isolated ▁intern ation ally . ▁ ▁In