Julia Gillard continued to differ as to the extent of Gillard's foreknowledge and planning of the replacement of Rudd. Rudd initially said that he would challenge Gillard, but it soon became apparent that he did not have enough support within the party to survive in his position. Hours before the vote on 24 June, he resigned as Prime Minister and Leader of the Labor Party, leaving Gillard to assume the leadership unopposed. Treasurer Wayne Swan was at the same time elected unopposed to succeed Gillard as Deputy Leader. Shortly afterward, Gillard was sworn in as the 27th Prime Minister of Australia by
Acting prime minister is on vacation, or is in ill health. In the early 20th century, when travel by ship was still the norm, it was not uncommon for there to be an acting Prime Minister for months on end. The deputy Prime Minister is usually designated as the acting Prime Minister, although another senior member of the government may fill the role if both the Prime Minister and deputy Prime Minister are unavailable. An acting Prime Minister is required quite frequently – for instance, between 3 December 2007 and 23 February 2009 (during Kevin Rudd's first term), Julia Gillard acted as Prime