From 1/12/07 changes made by the MHA 2007 give civil partners equal status to husbands and wives when determining a patient's nearest relative. See s26.
84. Section 26 amends the list in sections 26 and 27 of the 1983 Act of those persons who may act in the role of NR of a patient, by giving a civil partner equal status to a husband or wife.
Mental Health Act 2007 Explanatory Notes - page 1