A Christian B&B landlady is fighting a judge's ruling that she unlawfully discriminated against a gay couple - insisting she only refused them a double bed because they were not "married."

Susanne Wilkinson refused to let Michael Black, 62, and John Morgan, 56 - a gay couple who are not joined in a civil partnership - share a double bed in her Swiss B&B, in Cookham in March 2010.

Staunchly religious Mrs Wilkinson, a married mother-of-four, believes that sex before marriage is a sin and "against God's law" and says she refuses to let unmarried couples - whether straight or gay - share a bed under her roof.

However a judge at Reading County Court ruled last year that she had unlawfully discriminated against the gay couple on grounds of their sexual orientation and awarded Mr Black and Mr Morgan, who live in Brampton, Cambs, damages of £1,800 each.

As the gay marriage debate rages in Parliament, Mrs Wilkinson is now challenging the ruling at the Court of Appeal, insisting she is in no way anti-gay and that her "old fashioned" beliefs on sex before marriage have not been afforded the respect they deserve.

Her counsel, Sarah Crowther, told Master of the Rolls, Lord Dyson, Lady Justice Arden and Lord Justice McCombe: "This is an appeal about whether a Christian owner of a B&B guest house was allowed not to permit persons who were not married or in a civil partnership access to a double room.

"It is not any part of her case to undermine the rights of Mr Black and Mr Morgan. But it is her case that the judge erred in failing to balance those rights against her own rights.

"Mrs Wilkinson believes that homosexual or heterosexual sexual relations outside marriage are wrong and against God's law.

"It may be thought to be somewhat old fashioned, but we think that fact should not lead to any conclusion that those beliefs are unworthy of respect."

Henrietta Hill, for Mr Black and Mr Morgan, said: "The reason they were treated less favourably is that they were two men and they were two gay men. That is the beginning and end of it.

"The requirement that the couple must be married is necessarily linked to heterosexual orientation.

"There is no homosexual couple, whether in a civil partnership or not, who could be married. Mrs Wilkinson's provision, criterion or practice, was to the general disadvantage of homosexual people.

"They were never asked if they were in a civil partnership; they were simply turned away. We don't seek to impugn the beliefs of Mrs Wilkinson and her husband (but) a balance needs to be struck."

Recognising the importance of the case, the judges reserved their decision at the end of the hearing, until a later date, yet to be set.