Change of party leader: Beginning of Hayes's period in office: Premier Lee led his party to victory at the 1919 House of Assembly elections under the banner of the newly formed Nationalist Party (Nationalists). The Nationalist Party was formed in 1917 in response to political divisions over Australia's role in the First World War and the use of conscription for military service. Supporters of the Liberal Party combined with elements of the Australian Labor Party to form the new party. At the Assembly election in June 1922, the anti-Labor forces were split between the Nationalist Party and a newly formed Country Party, leaving Lee with only a minority of National Party support in the Assembly. Lee was instructed by the members of the Nationalist parliamentary party to seek an arrangement with the Country party members to support a coalition government. Lee was unsuccessful and resigned the leadership of the Nationalist Party over the issue of the involvement of the Country Party in the choice of a joint party leader. He was replaced by Hayes who was chosen by a joint meeting of both parliamentary parties. Hayes was then commissioned as the Premier of a Nationalist Party and Country Party coalition government; see Hughes and Graham, p. 258, (see 'Sources', below).
Change of party leader: End of Hayes's period in office: 'In August  there was a government crisis involving administration of the State railways. Hayes invited the ministerial caucus to indicate its attitude to the Government, and, on hearing members' views, stated that he would resign. A meeting of Nationalist and Country [parliamentary] party members on 13 August chose [J C] Newton, over [former Premier] Lee and [A T] Marshall, as the new leader. However, Newton proved unable to form a ministry as Lee and other former Ministers refused to serve under him, and a second meeting on the 14th elected Lee. Hayes then tendered his resignation,...', Hughes and Graham, p. 259, (see 'Sources', below).
References: For a description of the style of parliamentary government in this period, see John Reynolds, 'Premiers and Political Leaders', in F C Green (editor), Tasmania: A Century of Responsible Government 1856-1956, pp 208-215, (Hobart: L G Shea, Government Printer, ), and note Terry Newman, Tasmanian Premiers 1856-1988: A Biographical Handbook, (Hobart: Tasmanian Parliamentary Library, ).
For a survey of Hayes's career, see Scott Bennett, ''Hayes, John Blyth (1868 - 1956)', Australian Dictionary of Biography, Volume 9, pp 239-240, (Melbourne: Melbourne University Press, 1983), online at:http://www.adb.online.anu.edu.au/biogs/A090244b.htm
'Ministries: Names of the Members of Successive Ministries which have held Office in Tasmania since the inauguration of Responsible Government, together with the Dates of Appointment and Retirement', Journal of House of Assembly, Second Session of the Forty-Fifth Parliament of Tasmania, Anno LIII and LV Eliz II; Session 2 of the 45th Parliament, Volume 251, 2004-2006, (Hobart: Government Printer, Tasmania); Colin A Hughes and B D Graham, A Handbook of Australian Government and Politics 1890-1964, (Canberra: Australian National University Press, 1968, SBN 708102700), and the website of the Parliament of Tasmania, http://www.parliament.tas.gov.au/