Around the 1930s and 1940s, the Belizean economy was mainly based on forestry which was an industry that was declining quickly at the time. The Labour movement came into being in 1934 when Antonio Soberanis Gómez led a group of struggling workers in the movement called the Labourers and Unemployed Association (LUA) to fight for more jobs and better pay. This made the people begin to question what being colonized by England had done for Belize. The people then thought how a country with many resources, wealthy landowners and merchants, had so much poverty.
Soberanis was jailed under a new sedition law in 1935. Still, the labour agitation achieved a great deal. Of most immediate importance was the creation of relief work by a governor who saw it as a way to avoid civil disturbances. Workers built more than 300 kilometres of roads. The greatest achievements of the agitation of the 1930s were the labour reforms passed between 1941 and 1943. Trade unions were legalised in 1941, but the laws did not require employers to recognise these unions. The Employers and Workers Bill, passed on 27 April 1943, finally removed breach-of-labour-contract from the criminal code and enabled British Honduras's infant trade unions to pursue the struggle for improving labour conditions. The General Worker's Union (GWU), registered in 1943, and quickly expanded into a nationwide organisation.
In the forestry industry's unemployment was eased during World War II (1939–1945) because workers in the thousands immigrated to Britain for jobs in forestry, to work in Panama for the building of the Panama Canal and to the United States of America for jobs in agricultural estates.
A branch of Marcus Garvey's Universal Negro Improvement Association (UNIA) movement was formed in British Honduras in 1920. William Campbell was president of the branch and Samuel Haynes was its general secretary. Garvey himself came to British Honduras to visit the newly formed branch in 1921, and spoke at public meetings about the aims and activities of the UNIA. His visit was a success, with one meeting attracting about 800 people. Despite the concerns of the governor and the British Honduras establishment, Garvey insisted he was a loyal subject of the British empire and that the UNIA wished only to help black people to build a government of their own. Samuel Haynes left British Honduras along with Garvey, something which hampered the organisation of the British Honduras UNIA Branch. The UNIA later became embroiled in a dispute over a legacy left by a benefactor by the name of Isaiah Morter, and even though Garvey returned to British Honduras in 1929 to try to settle the dispute, it split as a result. The UNIA therefore became relatively inactive from this time onwards, but despite this it still exercised great influence over the nationalist movement throughout the 1930s and 40s. Among its leaders were Lionel Francis, L.D. Kemp, and Calvert Staine, (vice president).
A radical nationalist group, first called the British Honduras Independent Labour Party, then the People's Republican Party, and finally the People's Nationalist Committee was formed in 1940. At their meetings the group called for the expulsion of all white men, the creation of a republic in union with the United States of America and the substitution as the national flag of the Union Jack with the flag of 'Belize Honduras'. Among its leaders were John Lahoodie, Gabriel Adderley, and its chief leader Joseph Campbell, also known as the 'Lion of Judah'. They were frequently attacked at their meetings by loyalists, and Campbell was repeatedly jailed. Lahoodie and Adderley later went to live in Guatemala.