Streeting replied: “The reason why, whatever my discomfort in this extremely sensitive area, I have made this decision is because I am following clinical advice and because, as health secretary, it is my responsibility to follow expert advice.”
He added: “Am I uncomfortable about puberty-suppressing hormones for this group of young people, for these particular conditions? Yes, I am, because of risks.”
But he said he had also been “uncomfortable” when he introduced a permanent ban “because I had to look children and young people in the eye, and their parents, who told me in no uncertain terms that that decision was harmful to them”.
Puberty blockers are drugs used to delay or prevent puberty happening.
The drugs are not prescribed on the NHS to children for the treatment of gender dysphoria outside clinical trials, with the agreement of devolved governments across the UK.
But a trial was recommended by the Cass Review, which concluded that the quality of research claiming to show the benefits of puberty blockers for youngsters with gender dysphoria was “poor”.
The PATHWAYS trial, which is due to start in January, will involve children who are being seen at gender clinics in England. The research team says their physical and mental health will be closely monitored and there will be a careful consent process involving both children and their parents. Researchers say they will also monitor bone density and brain development.
Objections to the trial include concerns about the potential impact on brain development, fertility and bone density, and the ability of young children to consent.
Streeting told MPs he had backed the trial because it had been recommended by Dr Cass in her review, which had been commissioned by his Conservative predecessor Sir Sajid Javid.
Conservative leader Kemi Badenoch has joined those calling for the trial, which will involve around 226 people aged between 10 and almost 16, to be stopped to prevent harm to children.
Dr Johnson, who branded it “Streeting’s trial”, told MPs: “The vast majority of the children in this trial are being unnecessarily experimented on with risky medications under his leadership.”