This project is made possible through the generous funding of the Leverhulme Trust (RPG-2013-175). We thank the Department of Political Science at UCL, the Constitution Unit at UCL and the Department of Politics at Birkbeck for ancillary support.

Our thanks to Phil Cowley, David Cowling, Max Gopelrud, David Sanders, Stephen Thomson and Ben Webb for sharing their advice, data and labour.

Our funders