Just did a bit of reading, the only difference I can see, is that in a divorce, one of the spouses can use adultery as a reason for said divorce, whereas in a civil partnership, adultery is not contemplated; from what I can see, this is, because adultery is defined as "sleeping with another person of opposite sex" - unlikely in a civil partnership as they are only available for homosexuals.
Estranged Son and Future Granddaughter
To think that London, or anywhere else for that matter, does not belong to any one demographic