brodies.com/insights/family-law/a-rose-by-any-other-name-alternatives-to-marriage/
www.weightmans.com/insights/outdoor-civil-weddings-and-partnership-ceremonies-and-what-is-the-difference-between-the-two/
www.weightmans.com/insights/what-is-the-difference-between-civil-partnership-and-equal-marriage/
Update:
www.tozers.co.uk/insights/change-to-marriage-and-civil-partnership-laws