See also:
viewpoints.stevens-bolton.com/post/102j660/juggling-the-political-hot-potato-cohabiting-couples-on-separation#page=1
www.stewartslaw.com/news/what-happens-to-a-property-when-an-unmarried-couple-breaks-up/
Update:
www.stewartslaw.com/news/the-state-of-cohabitation-law-in-the-uk/