Power in British political parties: Iron law or special pleading?

This article analyses the claims advanced by Robert McKenzie about the distribution of power in British political parties. It considers McKenzie's mode of analysis (with particular reference to Labour), his definition of terms, selection of evidence and interpretation of it. The major argument is that McKenzie over‐generalised from the events of the 1950s and 1960s and that subsequent events have severely undermined his thesis.