However, he spent most of the period between 1937 and 1945 in prison; he was arrested after the labour riots of 1937 and imprisoned until 1939.
After being released, he was re-arrested in at the start of World War II in 1939 because he was seen as a security threat to one of the British Empire's main supplies of petroleum.
After he was released from prison at the end of the war, Butler reformed the party to fight the 1946 general elections.
[2] In the 1950 elections it emerged as the largest party after the United Front did not run.
However, although it won six of the eighteen seats, the government was formed by Albert Gomes of the Party of Political Progress Groups.