With the increase in the electorate as the result of the Second and Third Reform Acts in the latter half of the 19th century came a corresponding increase in the importance of political parties. With this increase in the importance of party came the fear that the Burkean definition of the MP as a representative, owing his electorate his judgment as well as his industry would be replaced by a narrower conception of the MP as a delegate, returned to vote according to the dictates of party or ‘caucus’, subject to rejection by his party prior to an election, rather than the electorate as a whole at an election. This article examines the case of J.M. Maclean, Conservative MP for Cardiff 1895–1900, deselected by his constituency executive for his opposition to the Boer War, using it to shed light on the reaction of constituency parties in instances where MPs were felt to have overstepped the proper bounds of party discipline. The article concentrates on the relations between Maclean and his constituency party, crucial in Maclean's deselection. The limits of political dissent in time of war are examined, and the limitations placed by party on the freedom of action of individual MPs. In addition, the article gives glimpses of the tensions present in the Conservative-Liberal Unionist coalition which governed Britain between 1895 and 1906, particularly on perceptions of the controversial figure of Joseph Chamberlain among Conservative back benchers.