A conference advocating gay-to-straight conversion therapy is due to be held in London next month.
Two controversial Christian groups which support the 'ex-gay movement' are due to hold a conference on curing homosexuality, pinknews.co.uk has reported.
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The conference by the Christian Legal Centre and Core Issues Trust asks the question: "Homosexual orientation and practice - what did Jesus say? Straight, gay, bisexual - what about ex-gay and post-gay? 'Don't want to be gay anymore? Sorry we're not allowed to help you!' Is that ethical?"
Andrea Minichiello Williams, who founded Christian Concernin 2008 to protect "Britain's Judeo-Christian values", will be on the panel along with Dr Michael Davidson, the founder of Core Issues Trust.
The Trust's slogan read: "Not Gay. Ex-Gay, Post-Gay and Proud. Get over it!"
The posters were in direct response to the lesbian, gay and bisexual rights charity Stonewall posting posters stating: "Some people are gay. Get over it!"
The Stonewall advert on buses in London
The High Court ruled in favour of TfL in March this year, stating that running the Trust's adverts could cause "great offence." The Trust has now taken the case to the Court of Appeal.
Dr Davidson has said he is making a stand for the rights of people like himself.
Dr Mike Davidson, of Core Issues Trust
Describing himself as having had homosexual feelings supressed by therapy, enabling him to marry and have children, said he was campaigning for the right to be recognised.
He told HuffPost UK at the time: "I am tired of being told I am a repressed gay and that I am homophobic. It's too easy folks, it belittles me because I disagree, and that is not right. It is profoundly uncomfortable that we cannot talk about this.
"We are not damaging gay folk, we are damaging people that do not want to go in that direction and want to seek help, but cannot."