The Conservative Party has vowed to block the NHS trial investigating puberty blockers for children with gender dysphoria following the Medicines and Healthcare products Regulatory Agency’s (MHRA) recent approval to resume the study. Kemi Badenoch, the Tory leader, announced plans to force a Commons vote aimed at preventing children as young as 11 from receiving the treatment under the Pathways trial.

The trial, led by researchers at King’s College London (KCL) in partnership with the South London and Maudsley Hospital, was initially paused in February after the MHRA raised concerns over “potentially significant” risks to participants. However, on June 19, the regulator approved new protocols that allow the study to restart, intending to enroll girls aged 11 and older and boys aged 12 and above starting August 1.

Badenoch criticized the decision, arguing that the evidence supporting the use of puberty blockers on children is weak and describing the trial as experimental and risky for vulnerable young patients. She emphasized that the government should immediately halt the trial, accusing ministers of succumbing to pressure from trans activists and bureaucrats. Badenoch pledged to pursue legislative amendments to the Health Bill, currently under consideration in the Commons, to prevent the trial from proceeding. If Labour refuses to intervene, she said the Conservatives would seek to block the Pathways trial through parliamentary means.

The announcement places Health Secretary James Murray under significant pressure as critics question the ethics and safety of the research. The trial was developed after an indefinite ban on puberty blockers for under-18s was imposed by the health secretary at the time, Wes Streeting, in December 2024. Streeting’s decision followed advice from the Commission on Human Medicines citing “unacceptable safety risks,” although he allowed the Pathways trial to proceed, following recommendations from the Cass review, a landmark report on NHS gender services for children.

Separate from parliamentary efforts, campaigners led by James Esses, a therapist and gender-critical activist, have launched a legal challenge against the Department of Health and Social Care (DHSC) and the Health Research Authority (HRA). They argue that the ethical approval process for the trial contained “serious flaws.” Esses, along with the Bayswater Support Group and detransitioner Keira Bell, is seeking an emergency injunction to halt recruitment until a judicial review scheduled for July 27.

According to Esses, assurances were initially given that recruitment would not start before the judicial review concluded, but delays in legal proceedings have complicated the timeline. He warned that the trial’s imminent resumption risks exposing children to harmful treatments. “If something’s dangerous enough to ban, it’s too dangerous to trial this on children,” he said.

In response, the Pathways research team reaffirmed their commitment to rigorous safety standards, emphasizing that scrutiny is welcomed and that the trial aims to provide robust evidence on the benefits and risks of puberty suppression in young people with gender incongruence.

A DHSC spokesperson underscored that participant safety remains the utmost priority and stated that the MHRA has introduced strengthened safeguards for anyone participating in the trial.