Lesley Pilkington, 60, a therapist for 20 years, is accused of 'praying to God' to 'heal' the patient .
Mrs Pilkington, will appear at a landmark disciplinary hearing this week where she faces being stripped of her accreditation to the British Association for Counselling and Psychotherapy.
Gay lifestyle: A small group of councilors believe all men are born heterosexual, but some choose to live as homosexuals
A small group of counsellors believe all men are born heterosexual, but some choose a gay lifestyle which can be changed through therapy.
Mrs Pilkington, a devout Christian, told the Sunday Telegraph that her method - Sexual Orientation Change Efforts - is legitimate and effective.
Some of the therapy, from the U.S.,involves sending patients away with straight men to 'encourage their masculinity and 'in time develop healthy relationships with women.'
But the counselling has been described as 'absurd' and the Royal College of Psychiatrists said the 'so-called treatments of homosexuality' allow prejudice to flourish.
Mrs Pilkington's 29-year-old son is gay, but she said he simply has a 'homosexual problem.'
She treated journalist Patrick Strudwick at her private practice based at her home in Chorleywood, Hertfordshire, after he approached her at a Christian conference.
He recorded the sessions on a tape machine strapped to his stomach. Asked if she viewed homosexuality as a 'mental illness, an addiction or an anit-religious phenomenon', she replied: 'It is all of that'.
In the disciplinary letter sent to her by BACP, she is accused of having an 'agenda that homosexuality is wrong and that gay people can change and you allegedly attempted to inflict these views on him.'
Mrs Pilkington accused Strudwick of entrapment. She said: 'He told me was looking for a treatment for being gay.
'I told him I only work using a Christian biblical framework and he said that was exactly what he wanted.'
Her defence is being funded by the Christian Legal Centre which has instructed a leading religious rights barrister to fight the case.