The origins of the CWI can be traced to a group of British Trotskyists which were expelled from the USFI in 1965,[1] after disagreements regarding the Colonial Revolution, Guerillaism, Studentism and the post war boom.

[3][4][5] In the early years of the international, sections generally pursued a policy of entryism into social democratic or labour parties.

One section has representation in a state parliament, the Socialist Party, which at its height had three TDs in Dáil Éireann in the Republic of Ireland.

In Brazil, CWI members helped found the P-SOL Socialism and Liberty Party after left wing parliamentarians were expelled from the PT.

[19] Notable national sections from this time include: Historical Historical Sekuizyuji Haangdung Eksath Samajavadi Pakshaya / Aikkiy Cōcalic Kaṭci Youth against Racism in Europe (YRE) was an anti-racist organisation founded by the Committee for a Workers' International (the international network of the Militant tendency) it campaigned among young people in 16 countries in Europe.

YRE was formed by Militant Labour as an alternative to the rival Socialist Workers Party (UK)'s Anti-Nazi League (ANL), relaunched the previous year, and the Anti-Racist Alliance.

[22] In 2012, it called for the shutting down of the Golden Dawn organisation and its weekly newspaper on the grounds that "they propagate violent messages of hate".