Quizzed about the controversial move – which has forced the government to cancel a showpiece LGBT+ conference – the prime minister urged his critics to consider the “complexities and sensitivities”.
Mr Johnson claimed the decision did nothing to “diminish our determination to tackle prejudice wherever we can”, despite some leading Tory MPs joining the outcry.
And, asked why he is pulling back, he pointed to the need for parents to be fully involved in their children’s decisions about whether to undergo “irreversible treatments”.
Speaking at a hospital, the prime minister pointed to the issue of “Gillick competence”, a term in medical law to decide whether a child is able to consent to treatment, such as changing gender.
“I don’t think that it’s reasonable for kids to be deemed so-called Gillick-competent to take decisions about their gender or irreversible treatments that they may have. I think there should be parental involvement at the very least,” he said.
Mr Johnson also argued “biological males” should not be competing in women’s sports and that hospitals, prisons and changing rooms should have spaces “dedicated to women”.
“That’s as far as my thinking has developed on this issue. If that puts me in conflict with some others, then we have got to work it all out,” he said.
Revealingly, the prime minister said he was learning about what he called “novel concepts”, saying: “This is something that, frankly for people like me, it wasn’t something I thought I would have to consider in great detail.”
But Keir Starmer accused the government of “distraction tactics” in creating the row over conversion therapy, insisting int should be banned in all its forms.
And a former LGBT government adviser accused the government of “pathetic excuses” that were wrongly “conflating two very different things”.
Jayne Ozanne, who quit as an adviser over the “hostile environment” being created for LGBT+ people, said their trust in ministers is now “utterly broken”.
“Conversion therapy is about being told that you can never be trans, that there is an ideology at heart which stops someone being who they are,” she said.
“Of course these issues are complex, but that is why other international countries have found a way through.”
Mr Johnson said he was “sad” about the criticism that has forced the government to take the embarrassing step of cancelling the international conference in June.
“We will have a ban on gay conversion therapy, which to me is utterly abhorrent,” he said.
“But there are complexities and sensitivities when you move from the area of sexuality to the question of gender. There, I’m afraid, there are things that I think still need to be worked out.”
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