The provision was also used after the disappearance and presumed death of the Liberal Prime Minister Harold Holt in December 1967. The Liberal Party elected John Gorton, then a Senator, as its new leader, and he was sworn in as Prime Minister on 10 January 1968 (following an interim ministry led by John McEwen). On 1 February, Gorton resigned from the Senate to stand for the 24 February by-election in Holt's former House of Representatives electorate of Higgins due to the convention that the Prime Minister be a member of the lower house. For 22 days (2 to 23 February inclusive) he was Prime Minister while a member of neither house of parliament.