It took me a while to find this report
http://www.demos.co.uk/files/Faithful_citizens_-_web.pdf
but now that I have I’m fascinated. It’s fun seeing the Guardian struggle with the idea that religious people in the UK are significantly more likely to be left-wing than the general population:
http://www.guardian.co.uk/world/2012/apr/08/religious-people-more-likely-leftwing-demos