Adults will be able to change their gender legally without a doctor’s diagnosis under government plans that will transform British society.

Men will be able to identify themselves as women — and women as men — and have their birth certificates altered to record their new gender.

Ministers plan to tear up the existing rules that mean people have to live for two years as their desired gender before they can officially change sex.

A consultation on the Gender Recognition Bill, to be published in the autumn, will also include proposals to scrap the requirement that people get a formal medical diagnosis of “gender dysphoria” before applying to switch gender.

Critics warned that allowing people in effect to “self-identify” as a member of the opposite