A Catholic adoption agency in Scotland has been warned that it could lose its charitable status if it does not allow applications from gay couples.

The Office of the Scottish Charity Regulator (OSCR) has given St Margaret's Children and Family Care Society in Glasgow three months to change its policies to comply with equality regulations.

An inquiry into the adoption agency was prompted by a complaint from the National Secular Society.

The OSCR said St Margaret's "fails the charity test" and is operating in breach of the Equality Act 2010.

"The criteria it applies to people who enquire about assessment as prospective adoptive parents discriminate unlawfully against same sex couples," the OSCR said.

"The charity's preferred criteria prioritise couples who have been maried for at least two years: marriage is not available to same sex couples and this constitutes direct discrimination."

The OSCR concluded that the charity does not provide public benefit as the discrimination "causes disbenefit to same sex couples".

It warned that steps will be taken to remove St Margaret's from the Scottish Charity Register unless it amends its procedures to allow same sex couples to go forward for assessment as potential adoptive parents.