Detrosier attracted the further patronage of Francis Place who established him as a full-time lecturer. Shuttleworth arranged for the 1831 publication of "On the Necessity of an Extension of Moral and Political Instruction among the Working Classes" and his work attracted the attention of Jeremy Bentham and Anne Isabella Byron, Baroness Byron. In 1831, Detrosier became secretary of the National Political Union whereby he became friends with John Stuart Mill and met Thomas Carlyle, Gustave d'Eichtal, George Birkbeck, and John Arthur Roebuck. Detrosier's new position in the liberal political establishment led him to work with health campaigner Thomas Southwood Smith.