On October 5, 1960, South Africa's white voters decided to make the country a republic. At the Prime Ministers' Conference in 1961, Verwoerd formally applied for South Africa to remain in the Commonwealth. The prime ministers were divided; Diefenbaker broke the deadlock by proposing that South Africa only be re-admitted if it joined other states in condemning apartheid in principle. Once it became clear that South Africa's membership would be rejected, Verwoerd withdrew his country's application to remain in the Commonwealth and left the group. According to Peter Newman, this was "Diefenbaker's most important contribution to international politics ... Diefenbaker flew home, a hero."