A moderate nationalist and leading figure in pre-war Burmese politics, he was eventually displaced by the Anti-Fascist People's Freedom League, led by Aung San.
U Paw Tun was asked by Sir Reginald Dorman-Smith, the Governor of Burma, to form a new government, becoming prime minister in January 1942.
[2] When the Burmese government was evacuated to India following the Japanese invasion later that year, U Paw Tun followed the Governor to Simla along with another minister, Sir Htoon Aung Gyaw.
When the Governor assumed the powers of government under Section 139 of the Burma Act, Paw Tun ceased to be a minister and instead became one of the Dorman-Smith's advisers, to whom he was by then closely associated.
In 1945, he returned to Burma with the Governor and became Home and Judicial Minister in the new Executive Council as well as its head, over the objections of the Anti-Fascist People's Freedom League (AFPFL).
U Paw Tun in turn pushed for the arrest of Aung San, the leader of the AFPFL, for the murder of a village henchman during the war.