Zac Goldsmith has likened treatments for transgender children to "lobotomies", in comments which have been condemned by trans campaigners as perpetuating a "dangerous rhetoric".
Responding to a tweet about puberty blockers by a former Downing Street aide, Goldsmith said: "Putting children on this brutal pathway will one day be seen in the same way we now view lobotomies."
His words have been criticised by a trans charity, who said they could add "further difficulty" to trans people's lives.
Puberty blockers are drugs used to "pause puberty" and are given to a child experiencing gender dysphoria to allow them more time to consider their options.
In 2020, the High Court made a landmark judgement ruling it was “highly unlikely” that a child aged 13 or under would be able to consent to the hormone-blocking treatment, and that it was “very doubtful” that a child of 14 or 15 would understand the long-term consequences.
The ruling said doctors “may well consider it appropriate” to get the court’s approval for any puberty blocker prescription.
However, in September 2021, the Court of Appeal overturned the ruling, finding that doctors should be able to exercise their clinical judgment rather than needing a court’s approval to provide such courses of treatment.
Lui Asquith, Director of Legal and Policy at Mermaids, a charity which supports trans and gender-questioning youth, told Yahoo News UK it was "disheartening" to see a UK politician "demonising" a portion of trans healthcare and portray them as having mental health difficulties.
"Lobotomies were used to treat severe mental health in the early 20th century," they added.
"So it's that whisper to the idea of trans being a mental health illness which we know is not true and not correct, and adds to a really dangerous rhetoric thats being pushed onto a very vulnerable population.
"Trans people have a higher risk of mental health because of what they face, not because they're trans. It's an important nuance."
"It's also nod to it being an experiment, which is a term which has been used regularly in terms of puberty blockers being used the past few years without acknowledging that puberty blockers have been used for a long period of time."
Goldsmith's words could add "further difficulty" to young trans people's lives, Asquith warned.
They said: "His words nods to and speaks to wider rhetoric around trans youth healthcare, but we should always pull ourselves to the heart of the issue which are young people who need support.
"The rhetoric that we are seeing in Zac's tweet adds to more difficulty to them being understood and believed, and them not being seen as different or a-typical."
Asquith added that his ideas seemed to come from an "idea that young people don't have agency, but the treatment always stems from young people coming out".
Yahoo News UK has contacted Zac Goldsmith for a response to the criticism.
What are puberty blockers?
Puberty blockers are drugs used to "pause puberty", allowing a child who is experiencing gender dysphoria more time to consider their options.
Children can only become eligible for the treatment after puberty has started, and waiting lists for the UK's only Gender Identity Development Service (GIDS) mean someone experiencing gender dysphoria is likely to have to wait three years before seeing a specialist.
The NHS defines gender dysphoria as "a sense of unease that a person may have because of a mismatch between their biological sex and their gender identity".
The drugs suppress the hormones which tell the body to begin developing things such as a deeper voice, breasts, or to begin menstruation.
The medications are also used to treat children who have medical conditions which cause them to go through puberty prematurely.
What are the effects?
According to the NHS, little is known about the long-term side effects of hormone or puberty blockers in children with gender dysphoria.
GIDS says the physical effects are reversible if the treatment is stopped, but warns the psychological effects are unknown.
The NHS also states that it is also not known whether hormone blockers affect the development of the teenage brain or children's bones. Side effects may also include hot flushes, fatigue and mood alterations.