 He became associated with the fledgling anarchist newspaper "Liberty," edited by J. Tochatti, formerly of the Hammersmith branch of the Socialist League.In September 1903 and March 1904, Mainwaring published two issues of a short-lived newspaper called "The General Strike," a publication which made detailed criticisms of the "officialism" of union bureaucracy and which publicised strikes in Europe making use of syndicalist tactics.In his later years, Mainwaring lived in London.