A Christian couple who are being sued for banning gay couples from sharing rooms at their Cornwall hotel are expected to claim they were set up by Stonewall.

Peter and Hazelmary Bull, who own the Chymorvah Private Hotel in Cornwall, are being sued for discrimination on the grounds of sexual orientation.

In 2008, they refused to let civil partners Martin Hall and Steven Preddy stay in a room with a double bed because they are both men.

Mr Hall and Mr Preddy, who are seeking £5,000 in damages, are taking the couple to court today.

The Buss will reportedly claim that they were set up by gay charity Stonewall, which contacted them a month before Mr Hall and Mr Preddy made the booking.

They are set to claim that there was a carefully-orchestrated campaign against them.

However, Stonewall said this was untrue and that it had contacted the Bulls after another, separate complaint from a customer.

A Stonewall spokesman said: “It’s been illegal since 2007 for businesses to discriminate against lesbian, gay and bisexual customers.

“Stonewall contacted the Chymorvah hotel in response to a complaint to our InfoLine from a caller about their discriminatory booking policy. We sent them a letter reminding them that the law had changed and what they were doing was illegal and offered to update them if necessary.

“The complaint to our InfoLine was unrelated and is entirely separate to the current court case.”

Mr and Mrs Bull told the Sunday Times that they had received “violent” anonymous letters and telephone calls threatening to destroy their business.

Police patrols around their guesthouse and their local church have been increased, they said.

The Bulls state on their website that they will only let heterosexual married couples share rooms. They say that their longstanding policy applies to all unmarried couples, whether gay or straight.

Their legal defence is being financed by The Christian Institute.

Yesterday, a letter from two conservative bishops was published in the Sunday Telegraph.

The Bishop of Winchester, Rt Revd Michael Scott-Joynt, and the former Bishop of Rochester, Rt Revd Michael Nazir-Ali, wrote: “Mr and Mrs Bull’s understanding of marriage is the same as that of English law and the Christian church. Their guesthouse is also their home. Their policy may seem traditional but, of itself, there is nothing wrong with that.”

They added: “Liberty of conscience must not be confined to the mind. It is meaningless unless it includes the freedom to stand by our principles publicly.”