A Christian couple who say they have been barred from fostering because of their "traditional" views on homosexuality are to take their case to the High Court.
Eunice and Owen Johns said their local council's fostering panel rejected them as carers because they could not tell a child a homosexual lifestyle was acceptable.
The Johns will go before the High Court on Monday to ask for clarification on the council's position on the suitability of foster carers who have traditional beliefs regarding sexual ethics.
The case, thought to be the first of its kind, has been described by Christian lawyers as vital for Christian freedoms.
The Pentecostal Christian couple from Derby, who have fostered almost 20 children in the past, are not homophobic, according to a legal representative.
But they are against sex before marriage - and by marriage, they do not recognise civil partnerships between gay couples.
Their beliefs are at odds with Derby City Council's equality policy, which was drawn up under the terms of the Sexual Orientation Act.
The case has been taken up by the Christian Legal Centre, who said it was the first time a court had been asked to decide how local authorities should deal with foster carers who have traditional views on sexual ethics.
It said in a statement: "The council has an obligation to respect the Johns' religious beliefs, but also to comply with equality law, which prohibits discrimination because of sexual orientation. The case will decide whether the Johns will be able to foster without compromising their beliefs."
But Stonewall, the lesbian, gay and bisexual rights charity, backed the council's stance. Chief executive Ben Summerskill said: "Too often in fostering cases nowadays it's forgotten that it is the interests of a child, and not the prejudices of a parent, that matter."