John Cain had led the Labor Party in Victoria since 1937, and had been Premier since defeating
John McDonald's
Country Party government at the
1952 election, forming the first majority Labor government in Victoria's history. The leader of the opposition
Liberal and Country Party,
Trevor Oldham, had died on 2 May 1953 in a plane crash on his way to attend the coronation of
Queen Elizabeth II. Oldham's deputy,
Henry Bolte, succeeded him a few days later. The election was triggered by events related to the
Australian Labor Party split of 1955, in which followers of
B. A. Santamaria's "Movement"—Catholic, anti-Communist, right-aligned members of the
Labor Party—were accused by federal leader
H. V. Evatt of contributing to his loss of the
1954 federal election to
Robert Menzies. The federal executive set about expelling "disloyal" members who supported the Movement. In the Victorian parliament, the anti-Communists were known as the Barry–Coleman group after the leaders of the faction:
Bill Barry in the Legislative Assembly and
Les Coleman in the Legislative Council. In April 1955, Barry and Coleman wrote to Cain requesting a unity conference, but the request was rejected, with Cain telling the group that they could only achieve unity within the ALP, by accepting the authority of the Labor federal conference and executive, and the Victorian central executive. On the night of 19 April, Bolte moved a
motion of no-confidence against Cain's government in the Legislative Assembly. In the early hours of 20 April, following a twelve-hour debate, eleven
anti-Communist Labor members
crossed the floor to support Bolte's motion. With his government defeated, Cain sought and received a dissolution of parliament later that day. ==Key dates==