Children as young as five will be taught about transsexual rights under new Government guidelines.
The Government says its guidance, which was published last week, is aimed at tackling ‘gender bullying’.
But parents groups have accused ministers of trying to turn children into “confused mini adults”.
The Government guidance suggests schools use their prospectus as well as newsletters, website, displays and school events to promote the school’s stance on the issue.
Schools are also pointed to material from the gay lobby group Stonewall.
Margaret Morrissey, of Parents Outloud, raised concerns.
She said: “The Government should stop interfering with parents bringing up their children and focus on teaching.”
She added: “This has nothing at all to do with academic learning.”
The Government has launched a public consultation on the proposals.
Defending the scheme Vernon Coaker, the Schools Minister, said the guidance had been published to help teachers deal with “sexual, sexist and transphobic bullying.”
He said: “The Government is committed to tackling gender bullying more widely through our violence against women and girls strategy.”
The Government’s new Children, Schools and Families Bill contains plans to force schools to teach children about sex and relationship education (SRE) from the age of five.
It also says whenever SRE is taught, civil partnerships must be discussed.
Parents will also lose the right to withdraw their children from SRE lessons when they turn 15 if the Bill is passed next year.
Faith schools will not be able to opt out of teaching any aspect of the new SRE programme, but Children’s Secretary Ed Balls said they may teach the topics according to the “tenets of their faith”.
One newspaper columnist described the plans as “simply a cynical method of enforcing anti-Christian values on faith schools”.