This thesis examines the impact of the introduction of the MMP electoral system on the behaviour of electorate level political party activists. The theoretical framework used incorporates literature on both electoral systems and party organisations, particularly the work of Maurice Duverger (1954). Three hypotheses are presented dealing with how electorate organisations are likely to be affected by the change in electoral system both as individual entities (greater difficulty in performing basic functions) and as part of the wider party organisation (greater centralisation and stronger articulation). These are tested using a qualitative analysis of information gathered from a case study of the New Zealand National Party in the Banks Peninsula electorate. This thesis concludes that electorate organisations have not been significantly affected by the introduction of MMP. Minor changes in relation to the functions they perform have in most cases been counter­ balanced by either legislative changes or the stability of branch organisations within the electorate. It is also concluded that, while articulation has strengthened and centralisation increased within the National Party organisation, the strength of its democratic and decentralised tradition is such that the implications for electorate organisations will be minimal. Perhaps the only exception is in relation to campaigning, where this study has shown that electorate activists generally have yet to make the cultural transition to the MMP environment and the new significance of party over local candidate.