She agreed to help Patrick Strudwick become heterosexual without realising he was an undercover journalist and gay rights campaigner who had a tape recorder strapped to his stomach.

Mrs Pilkington, a devout Christian who says she 'understands the issues' because her son is gay, has treated around ten patients using the controversial Sexual Orientation Change Efforts programme over the past decade.

In tapes of her sessions with Mr Strudwick he asks her if she views homosexuality as 'a mental illness, an addiction or an anti-religious phenomenon'.

She replies: 'It is all of that.'

He complained to the BACP and it launched disciplinary proceedings against her, accusing her of 'praying to God to heal him [Mr Strudwick] of his homosexuality' and having an 'agenda that homosexuality is wrong'.

Mrs Pilkington, who is fighting the case, accuses him of entrapment. Her defence is funded by the Christian Legal Centre.

She said she wanted to help ­others who were in a 'similar place' to her 29-year-old son who, she insisted, was 'heterosexual. He just has a homosexual problem'.

'I am not in this because I am judging people,' she said. 'I am in it because I understand what the issues are.

'I have been able to help my son. We have gone through a process.

'[My son] is still gay... we are developing a relationship that was quite difficult for many years but is now coming back in a very nice way. I am confident he will come through this and he will resolve his issues and that he will change.

She saw Mr Strudwick at her practice in Chorleywood, Hertfordshire. She said: 'He told me he was looking for a treatment for being gay. He said he was depressed and unhappy and would I give him some therapy. I told him I only work using a Christian ­biblical framework and he said that was exactly what he wanted.'

She told the Sunday Telegraph: 'We say everybody is heterosexual, but some people have a homosexual problem. Nobody is born gay. It is in the upbringing.'

But Mr Strudwick, who runs ­campaign group the Stop Conversion Therapy Taskforce, said: 'Every major mental health organisation in Britain and America is opposed to attempts to change someone's sexuality... because there is good evidence not only that it doesn't work but that it is harmful.

'If a black person goes to a GP and says, "I want skin bleaching treatment", that does not put the onus on the practitioner to deliver the demands of the patient. It puts the onus on the healthcare practitioner to behave responsibly.'

A spokesman for the Christian Legal Centre said it was defending Mrs Pilkington because she was 'lied to and misrepresented'.

END