Simply a matter of context? Partisan contexts and party loyalties on free votes

While recent studies suggest the party loyalties of Members of Parliament (MPs) influence voting behaviour on free votes independently of personal preferences, it remains to be seen to what extent party loyalties influence MPs’ voting behaviour more generally. To this end, this paper examines the impact of the partisan context of the vote on the effects of party loyalties. Using data from 20 divisions decided largely as free votes and controlling for personal preferences using a survey measuring MPs’ attitudes, the analysis shows that the effect of party loyalty on voting behaviour is strongest under the most partisan conditions: when the outcome is anticipated to be close and most consequential to the success/failure of a bill. These findings suggest party loyalty effects may emerge on other highly partisan divisions with partisan consequences, and not appear on less partisan divisions.