Norfolk MP and former prime minister Liz Truss has said the government's long-awaited draft transgender guidance for schools "does not go far enough" and will be exploited by "activists".
The Department for Education has published instructions for schools and colleges on how best to support pupils questioning their gender, after it was delayed from the summer.
The non-statutory guidance says "parents should not be excluded" from decisions taken by a school or college relating to requests for a child to "socially transition", such as wishes to change names, pronouns and clothing.
Schools and colleges in England have been told there is "no general duty" to allow children to change their gender identity.
It adds schools should provide separate toilets for boys and girls aged eight and above, and changing rooms and showers for boys and girls who are aged 11 years or over at the start of the school year.
But South West Norfolk MP Liz Truss - who this month introduced a Parliamentary Private Members Bill to ban biological males from entering single-sex spaces, such as toilets and changing rooms, and prevent under-18s from taking puberty blockers or cross-sex hormones - criticised the guidance.
She said: "Today's guidance does not go far enough. During the many months we have been waiting for its publication, it has become increasingly clear that non-statutory guidance will provide insufficient protection and clarity, and that a change in the law of the land is required.
"I fear activists and others will be able to exploit loopholes in the guidance and the existing legal framework to pursue their agenda, leaving children at risk of making irreversible changes and with single-sex spaces not sufficiently protected."
She urged the government to back her bill.
Prime minister Rishi Sunak's official spokesman, responding to Ms Truss’ criticism of the non-statutory guidance, said: "We are confident this is the right approach. It’s also the fastest way to provide protections to parents, pupils and teachers.
"Seeking to legislate would require considerable additional time."
Geoff Barton, former head of King Edward VI School in Bury St Edmunds and general secretary of the Association of School and College Leaders, said: "It is frustrating that ministers have dithered and delayed for so long, but we welcome the fact that draft guidance has now been published.
"We’re now going to spend some time discussing the details with school and college leaders before responding in full to the consultation."
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