Leading schools, including Eton, Westminster and High Wycombe, are also being told they should display an ‘equality pledge’ for all visitors to read and sign at reception.

Teachers are also being taught new vocabulary to address new gender identities, including ‘genderqueer’,a term used by individuals who identify as neither male nor entirely female; or ‘pansexual’, which is someone attracted to men, women and transsexual.

It is understood a growing number of both state and private schools are dealing with students who reject ‘the binary system of gender’ and whose sexual orientation is more fluid with some identifying themselves not just as lesbian and gay.

Schools have already introduced both gender-neutral uniforms, including Brighton College in the private sector and roughly 80 state schools, including Allens Croft.

Single-sex private schools have also been told to remove the use of terms like “girls”, “young women” or “young ladies” and replace it with more neutral terms like “pupils” or “students”.