Lesley Pilkington was informed of the decision by the British Association for Counselling and Psychotherapy (BACP) this week following a lengthy appeal.
In 2009, gay journalist Patrick Strudwick approached Mrs Pilkington at a Christian conference and pretended to be a Christian in need of help with unwanted homosexual attraction.
Mrs Pilkington agreed to help him and two counselling sessions were held in which Mr Strudwick told her he wanted to leave the homosexual lifestyle and to change.
Mr Strudwick secretly recorded the sessions and then lodged a complaint with the BACP to have her struck off. He also wrote about his experience in The Guardian.
The appeal panel found this week that Mrs Pilkington was guilty of professional malpractice.
It ruled she should lose her senior accredited status because she should not have assumed that Mr Strudwick wanted to proceed under the same therapeutic approach that she offered, despite both of them agreeing to do so.
Although the panel agreed that the controversial therapy itself did not necessarily breach professional standards, it added: “There is a wide range of opinion and beliefs among those who call themselves Christians.
“Mrs Pilkington wrongly and negligently jumped to the conclusion that Mr Strudwick properly understood her therapeutic model and the belief system underlying it.”
The panel also concluded that Mr Strudwick was a real client, despite being an undercover reporter who approached her on false pretences.
However, it criticised Mr Strudwick’s conduct, saying that he had “in significant ways deliberately misled her into believing that he was comfortable and accepting of her approach, such as saying Amen at the end of prayers”.
“In his persistent questioning he manipulated the content of the sessions to a considerable extent in order to meet his own agenda,” the panel concluded.
Despite the ruling, the BACP still recognises reparative therapy, leaving councillors free to continue offering it to clients.
Mrs Pilkington voiced fears for other Christian counsellors who offer reparative therapy.
“Who is going to protect Christian counsellors from continued harassment?” she said.
“We are supposed to live in an inclusive and diverse society. Does that then mean it’s inclusive and diverse for everyone except those who want to leave their same sex attraction, and those therapists who want to help them?”
Andrea Minichiello Williams, head of the Christian Legal Centre, which defended Mrs Pilkington said: “Lesley has been penalised because she was targeted as a Christian and because she believes that people are free to choose to change their behaviour if they wish.
“For Patrick to seek to take away her professional accreditation and malign her in this way exposes the more sinister side of the homosexual lobby. It’s incredibly intolerant.”