Lang was elected party leader in 1922 by the state caucus after a period of conflict between the NSW state executive of the party, dominated by the Australian Workers Union, and the federal executive. Lang's domineering manner resulted in increasing opposition to his leadership within the caucus. Particular areas of contention were the establishment of a Government Insurance Office and Lang's role in an attempt to increase the party's parliamentary majority through the appointment of Alick Kay as the consumer's representative on the Metropolitan Meat Board. However Lang continued to enjoy the overwhelming support of the party branches and the annual conference, which was the ultimate forum of party policy. Conflict within the caucus culminated in October 1926 with a leadership challenge by Peter Loughlin, Lang's deputy leader. Lang survived on the casting vote of the Chairman and he responded to the challenge by calling a special meeting of the party conference where, at his request, the conference took control of the pre-selection of party candidates and the election of the party leader. In the press these rule changes were referred to as "the red rules" or "the Lang dictatorship".
Lang still faced significant opposition within the caucus appointed cabinet, which he overcame by returning his commission as Premier to the Governor, Sir Dudley de Chair on 25 May 1927. This automatically resulted in the dismissal of his ministers. De Chair recommissioned Lang to form a caretaker government on the condition that he would recommend a dissolution of the Legislative Assembly and call an election. The government was formed solely of Lang supporters and Lang used the four months prior to the to ensure that his opponents were denied ALP pre-selection.The ALP lost the election but the caucus that was elected was under Lang's control and Lang was able to dominate the party in NSW for the next 12 years. In 1931 Lang had the support of the state party when he repudiated the Premiers Plans for economic management of the Great Depression and imposed a moratorium on the New South Wales government's overseas loans. This lead to a split between the state and federal labor movements and Lang's first break-away party, the Australian Labor Party (NSW), became the dominant Labor force in New South Wales from 1931 to 1936, when unity was again achieved.
Lang's lack of success at state elections (he was defeated in 1932, 1935 and 1938) eroded his support within the labour movement and resulted in some members of caucus, including Bob Heffron, to break away to form the Industrial Labor Party. In 1939, following intervention by the Federal Executive, a state conference unified the factions, reversed the "red rules" and returned the power of selecting the party leader to the caucus. Lang was replaced as state leader by William McKell. In the meantime, Left-wing forces had gained control of extra-parliamentary executive of the New South Wales Branch, and in 1940 the state executive adopted a resolution calling for a "Hands off Russia" policy, which was seen as opposing Australian involvement in World War II. Lang denounced this policy, and he and supporters again seceded from the Labor Party. The Federal Executive again intervened in the NSW Branch, and the left-wing elements known as the State Labor Party or State Labor Party (Hughes-Evans) were expelled with some members joining the Communist Party of Australia).
Lang meanwhile had formed a new party called the Australian Labor Party (Non-Communist), which operated in the Federal sphere from 1940 to 1941 but had only minority support in the Labor movement of NSW. Lang was finally expelled from the NSW state branch of the ALP (which had jurisdiction over membership) in 1943 after publishing articles attacking the premier William McKell. His party contested the 1944 state election, electing two members – Lang and Lilian Fowler, Australia's first female mayor. When Lang transferred to federal politics, he was succeeded as the Lang Labor member for Auburn by his son, James. Although both were re-elected in 1947, the party was essentially defunct by 1950 and Fowler and Lang were defeated.
Lang Labor's final appearance in federal politics came when Lang was elected to the House of Representatives for the federal seat of Reid at the 1946 election, being elected with the benefit of Liberal Party preferences. Lang was a nuisance to the Labor government of Ben Chifley, and his personal attacks on Chifley did Labor some damage. Lang was defeated at the 1949 election. In the double dissolution 1951 election he stood for the Senate, but was not elected.
Lang was re-admitted to the NSW branch ALP in 1971 at the age of 94 after a campaign by his protege Paul Keating
Melbourne University Press Melbourne ISBN 052284700