 John McEwen had announced in the lead-up to the spill that he would lift his party's veto on McMahon as prime minister.In March 1971, the Defence Minister, Malcolm Fraser, resigned from Cabinet and denounced Gorton, who then announced a leadership spill.The ensuing party room vote was tied, and under the party rules of the time this meant the motion was lost and Gorton could have theoretically remained as leader and Prime Minister.