In his review  of On the Edge, Bob Pitt, editor of the online Marxist journal WhatNext and a former member of one of the groups profiled in the book, the Workers Revolutionary Party (WRP), stated that the "central purpose of the book is to mount a slanderous attack on the revolutionary left, which often goes further than anything you might read in even the most anti-socialist sections of the bourgeois press."
Bob Pitt, editor of the online Marxist journal WhatNext and a former member of one of the groups featured in On the Edge, the Workers Revolutionary Party (WRP), stated that "the main objective of this book is to launch an unscrupulous attack on the revolutionary left, which often goes beyond what you might find even in the most anti-socialist parts of bourgeois media."