OXFORDSHIRE author Sheila Kitzinger said her daughter's High Court fight to have her gay marriage legally recognised in England is a question of justice.
University professors Celia Kitzinger, 49, from Oxfordshire, and her partner, Sue Wilkinson, were married three years ago in Vancouver, Canada where unions between same-sex partners are lawful.
The couple, who live in North Yorkshire, want their marriage to be given full legal status in the UK and protest that it is "insulting and discriminatory" to be offered civil partnership instead.
They are seeking a declaration under the Family Law Act that their marriage was valid at the High Court in London.
Their lawyers also claim that failure to recognise a same-sex marriage breaches the European Convention on Human rights.
Prof Kitzinger's mother, Sheila, the feminist pioneer and author, from Standlake, said: "It seems strange that Catholic countries like Belgium and Spain recognise their marriage, but England does not."
The case is being opposed by the Lord Chancellor, Lord Falconer, who claims that the wording of the Convention supports relationships between a man and a woman, and since the newly-introduced civil partnerships do the same, the women are not being discriminated against.