This paper focuses on how characteristics of parties and party voters explain the styles of representation emphasised within parties. Styles of representation are defined at the party level as the proportion of representatives within parties who are partisans, delegates or trustees. Each style manifests due to different incentives related to the characteristics of their party and/or their party voters. The findings show that the main explanatory factors for the proportion of partisans are parties’ leadership control over nomination and party socialisation. The main determinant for the proportion of trustees is how often parties have been represented in government. For delegates the results are mixed, but it is indicated that a high proportion of party identifiers among party voters is related to a high proportion of delegates within parties.