Christian hoteliers who banned a gay couple from sleeping in a double bed have told judges that they are entitled to impose their beliefs on guests in their home.

Peter and Hazelmary Bull were found guilty of discrimination and ordered to pay £3,600 damages at Bristol County Court after they turned Martyn Hall and his civil partner Steve Preddy away from their bed-and-breakfast business in September 2008.

The couple want the Appeal Court to overturn the decision because they did not discriminate against the gay couple but believed sex outside marriage was a sin for any couple.

Their lawyers explained to the judges that their objection was to a sexual practice, not a sexual orientation.

James Dingemans QC told the court: “The Bulls have operated a policy of restricting the provision of double rooms to married persons.

“They maintain that their policy is directed towards sexual practice and not sexual orientation, so there is no direct discrimination.

“Mr and Mrs Bull have been attempting to live and act in accordance with their religious beliefs, including the religious belief that, ‘monogamous heterosexual marriage is the form of partnership uniquely intended for full sexual relations between persons’ and that homosexual sexual relations as opposed to homosexual orientation and sexual relations outside marriage are sinful.

“They believed that permitting unmarried persons whether heterosexual or homosexual to share a double bed involved them in promoting a sin.”

Dingemanns suggested gay couple’s rights are not compatible with the Bulls’ rights, but a reasonable balance is not requiring the Bulls to promote the sharing of the room, which they believe to be a sin.

He also suggested that finding against the couple would lead them to close the business rather than be forced to offer rooms with double beds to unmarried couples.

In British law, a civil partnership imparts the same rights to a same-sex couple as marriage offers a heterosexual couple.