A senior Tory has allegedly stated a belief commonly held amongst central party managers everywhere: that their activists are ‘swivel-eyed loons’.  ‘Loon’, of course, is ultimate derived from ‘lunar’; the traditional belief that madness was more common during full moons. If we assume that voting Conservative is a form of madness, we can check whether a full moon does in fact impact upon the Tory vote by cross-referencing it with daily polls:

Loony ToriesSource: Polling undertaken on the UTC date of a full moon since beginning of 2012 when YouGov started recording UKIP separately.

There is a small but noticeable impact on both the Conservative and UKIP voting intention, with the former impact significant at the 5% level*. This is the inverse of what people who would also be happy to dub UKIP nutters would expect, and presents a danger for Mr Cameron. The first Thursday in May 2015 is the day after a full moon. The motion of our nearest celestial partner may yet cost the Conservatives the next election.

*This relationship attenuates as the data set grows, precisely as a non-crazy person would expect. From 2010 to the present day it’s practically insignificant. One could attribute the short-term effect to science being right or Nigel Farage being a werewolf.