Building upon Poole and Rosenthal’s NOMINATE technique and Kalt and Zupan’s residualization approach, I seek to disentangle the influences of constituency interests, party and ideology on the votes of MPs in the famous Repeal of the Corn Laws in 1846. I argue that while the Conservative party shared a distinct ideology, it was also a coalition of two interests-based alliances. The non-Peelite Conservatives represented mostly (protectionist oriented) agricultural districts while the Peelites represented districts with more free trade leaning interests. Before 1846, Peelites voted according to a general Conservative ideology, but in 1846 an abrupt change occurred: the pivotal Peelites appear to have eschewed Conservative party unity and their own personal ideology in favour more of the preferences of their constituents. Repeal appears to have gained passage as these MPs switched from voting more as trustees to voting more as delegates.