The Bishop of Hereford is being taken to an employment tribunal by a man who claims he was refused a job as a youth worker because he is gay.
The bishop carried out a "humiliating" interview, it is claimed
John Reaney, 41, of north Wales, said he was told after an interview that a job offer was a "formality" but was later summoned to meet the bishop.
He claims the Rt Revd Anthony Priddis then asked him "humiliating" personal questions about his private life.
The diocese said Mr Reaney had never been offered the job.
The two-day tribunal is due to begin in Cardiff on Wednesday.
Mr Reaney, who has previously worked as a youth worker for the dioceses of Norwich and Chester, says he was interviewed for the job by a panel of eight, including two vicars.
He claims he was then phoned to be told he was the unanimous choice for the job and the appointment would be confirmed, subject to approval by the bishop.
But when the bishop interviewed him, he claims he was quizzed over his sexual orientation and left in no doubt he would not be offered the job.
The Church of England's policy is that all homosexual staff must remain celibate.
Under the employment equality regulations, passed in 2003, it is illegal to discriminate in the workplace against people as a result of their sexual orientation.
The law contained an exemption for organised religion and this case is expected to act as a test over whether support staff in the Church of England are included in this.
Mr Reaney's case is being funded by the gay equality organisation Stonewall.
Its chief executive Ben Summerskill said he believed Mr Reaney had a strong case.
He said: "It is unacceptable for the Church of England to argue that they are entitled to refuse to employ someone who is very competent and experienced because of their sexual orientation.
"It is clearly pretty shaming for the bishop to spend Holy Week in an industrial tribunal."
A spokeswoman for the Diocese of Hereford said: "John Reaney did not get the job he applied for in the diocese.
"He was not offered the job and therefore an offer cannot have been withdrawn.
"We expect the same sexual standards of behaviour from support ministers, or lay ministers, as we do of clergy."