He has courted controversy as chairman of the controversial Hong Kong-based New Creation Association. The Christian organisation says on its website that it helps those in the process of 'giving up a lifestyle of homosexuality' through counselling.

The controversy has touched a nerve some 13,000 kilometres away because it appears to critics that the government is legitimising conversion therapy. Conversion therapy is the practice of changing someone's sexual orientation through therapy - based on the assumption that homosexuality is a sickness.

Among the groups due to join in the demonstration were Gay Asian-Pacific Islander Men of New York; Q-Wave: Queer, Asian, Visible, Empowered; and the International Gay & Lesbian Human Rights Commission

'It is appalling to us that conversion therapy is being exported to our countries of origin,' Dennis Chin, of the Gay Asian-Pacific Islander group, said. 'It's cultural colonialism, plain and simple.'

In the US, some therapists have tried to 'cure' homosexuality, through techniques ranging from cold showers to prayer to participating in 'heterosexual' activities like sport.

Hong dismissed such practices as 'stupid'. He said the New Creation Association did not force heterosexuality onto homosexuals, but helped them to find other sources of love from friends and family - and only worked with gay people who approached the association for help.

Hong said: 'We found that a lot of gay organisations and a lot of counsellors only provide gay-affirmative approaches that encourage people that are discouraged or dissatisfied with their homosexual relationships to continue.'

He believes the main causes of homosexuality include 'sexual abuse, gender identity disorder and trauma from heterosexual-love relationships'. He said conversion therapies had seen some success in academic studies.

Conversion therapy has been deemed 'unlikely to be successful and involve some risk of harm' by the American Psychological Association. It also said homosexual attractions were 'normal and positive variants of human sexuality'. The British Medical Association has called for the banning of such treatments.

Chin said: 'Conversion therapy has been discredited by major medical and mental health organisations. It's pseudo-science and it's homophobia. We are not suffering from a disease. There is nothing about us that needs a cure.'

There were protests from local gay groups when Hong spoke to social workers in June. The Social Welfare Department said it had also invited gay and lesbian groups to speak. 'Multiple perspectives [are] essential for social workers to make professional and independent assessments,' a spokeswoman said.