[Thanks to Dr John McMullen of Wrigleys Solicitors LLP for preparing this case summary]
Does an employer act unlawfully if he treats an employee less favourably, not because she is married, but because she is married to a particular man?
Yes says the EAT (HHJ McMullen) in Dunn v Insititute of Cemetry and Crematorium Management.
Mrs Dunn was employed as a technical services manager. Following a dispute over her employment terms she resigned and claimed constructive unfair dismissal. But she also claimed breach of the Sex Discrimination Act 1975 because she contended she was less favourably treated because she was married to Mr Dunn, with whom the employer was also in dispute. She was treated as an adjunct of him.
According to the EAT, reviewing the authorities, including Chief Constable of the Bedfordshire Constabulary v Graham  IRLR 239, section 3 of the Sex Discrimination Act 1975 (see Equality Act 2010, s. 8) could be construed as protecting the claimant by reason of her status, not only of being married, but also of being married to her husband. Furthermore, although the 1976 Equal Treatment Directive was not of assistance in this interpretation, the claimant's rights under Arts 8,12 and 14 of the ECHR were engaged, and section 3 of the SDA should be construed accordingly.