Campaigners in China have taken a clinic to court over its backing of gay-to-straight conversion therapy.

It’s the first time a lawsuit of this kind has been staged in the country.

China declassified homosexuality as a mental illness in 2001, but scores of clinics still seek to provide so-called conversion therapy.

Dr Zhou Zhengyou, of the Nanjing Urban Psychiatric Consultancy Centre, claims to have successfully “cured” 70% of his gay patients. He charges $120 (£70) a session.

LGBT activists have begun a legal challenge against the clinic. The case will be heard in court on Thursday.

Dr Zhou told the BBC’s World Tonight that he uses counselling alone and does not treat his patients with physical procedures offered elsewhere in China.

However, the practitioner defended the use of electric shock treatments, prescribed by other clinicians.

“One common method is electric shock. When the patient has a gay thought, we electrocute them or inject them with drugs that make them sick,” he said.

He added: “Gradually the patient will face disgusted about people of the same sex”.

Campaigners hope the pending legal action will change minds in China’s medical community.

A small protest against gay-to-straight conversion therapy was recently held outside a Beijing medical conference.

One placard read: “Being gay is not an illness”.

But some of the delegates were not convinced by the sentiment. “We cannot support homosexuality,” a doctor said. “Although we try to understand it,” his colleague added.

Last week, a gay man from Birmingham revealed he had been subjected to electric shock treatments as part of conversion therapy on the NHS in the 1970s.

In response, Care Minister Norman Lamb said homosexuality was “not an illness” and should never be treated as such.

Mr Lamb has ruled out the statutory regulation of psychotherapists in order to prevent doctors from referring patients to therapists who may seek to provide the treatment.

He favours instead a “voluntary register” for psychotherapists.

Earlier this year, Labour MP Geraint Davies published a Private Members’ Bill in Parliament aimed at banning the practice by regulating the psychotherapy sector.