Anna Friel as Vicky and Callum Booth-Ford as Maxine in the ITV drama Butterfly about a transgender child, which was shown last year

More than 30 families with transgender children are to lobby the government and the NHS against what they claim is “coerced medicalisation” — propelling vulnerable young people convinced they are the wrong gender towards treatments that risk leaving them infertile.

The group, provisionally called Our Duty, was formed after one mother went public to describe gender reassignment medication and surgery for those with autism or psychological problems as “state-sponsored sterilisation”.

The mother, whose daughter has attention deficit hyperactivity disorder (ADHD) and autistic traits and believes she is male, was speaking in London to governors at the only NHS trust specialising in the treatment of transgender young people.

Doctors at the Tavistock and Portman NHS Foundation Trust, which houses the Gender Identity Development Service (Gids), have