When Holt disappeared in December 1967, McMahon was assumed to be his probable successor. However, John McEwen, interim Prime Minister and leader of the Country Party, announced that he and his party would not serve in a government led by McMahon. McEwen did not state his reasons publicly, but privately he told McMahon he did not trust him. McEwen, an arch-protectionist, correctly suspected that McMahon favoured policies of free trade and deregulation.