Britons Publishing Society, founded in 1923, was an offshoot of The Britons.
Formally split from parent society in 1932
According to scholar Gisela C. Lebzelter, The Britons split because:
... internal disagreements proved paralysing. Seven members were excluded in November 1923, and three executives members, J. H. Clarke, the famous British homeopath, R. T. Cooper and W. A. Peters, seceded to establish 'The Britons Publishing Society'.
Carried on until the 70's. Not sure exactly when.