Hyndman said such practices are “really prevalent” in religious circles.
“When I came back to the UK, I visited my old churches in Northern Ireland and Edinburgh, and both tried to send me for conversion therapy.
“That means three unconnected churches all put pressure on me to change my sexual orientation.”
He said conversion practices could be “particularly pernicious” in a church setting.
“For a lot of people who belong to a church, their whole life is bound up in it: their family, friends, vocation, job, everything. The room for manipulation is massive.
“All of a sudden it can feel like your de facto options are: Agree to conversion therapy or lose everything you love.”
Much of the opposition to the bill is expected to come from religious groups.
Lynas acknowledged that “historically churches” did put “undue pressure” on gay people but said he is “waiting to hear evidence of that being done on any kind of scale in the last ten years”.
The bill says an offence would be committed if a victim suffered “psychological harm” as a result of conversion practices.
It defines this harm as fear, alarm or distress.
Lynas said this definition was too broad.
The Ban Conversion Practices Coalition – which includes groups such as The Rainbow Project, Here NI, Cara-Friend, Northern Ireland Humanists, Christians at Pride NI – have said they are satisfied the bill includes protections for freedom of speech, belief, and the delivery of legitimate healthcare and therapy.