Just as couples wishing to marry, whether heterosexual or same sex, can enter into pre- or post-nuptial agreements, so can same sex couples enter into pre- or post -civil partnership agreements.
The legal principles regarding pre- or post-civil partnership agreements are identical to those for pre-nuptial agreements governed by the 2010 Supreme Court case of Radmacher -v- Granatino and for post-nuptial agreements governed by the 2008 Privy Council case of MacLeod.
A court should give effect to a pre- or post-civil partnership agreement, as it should to a pre- or post-nuptial agreement, that is freely entered into by each party with a full appreciation of its implications, unless it is unfair. What this means is that the parties to a pre- or post-civil partnership agreement should have separate and independent legal representation, and there should be proper financial disclosure.
As far as fairness is concerned, an agreement should not leave one of the parties unable to meet his or her basic needs, and any children must be properly provided for.