 She remained a formal but dissident member of the SLL until the formation of the Bulletin Group in 1974-5.She took public stands as a Trotskyist, condemning Healy's allegations that Joseph Hansen, one of the American Socialist Workers Party leaders, was a CIA agent.Hamilton co-founded the British Committee for the Reconstruction of the Fourth International (BCRFI) after disagreements with Robin Blick and John Archer within the Bulletin Group, which then split.