Children as young as five could be given compulsory sex education, it was revealed yesterday.
The prospect emerged as ministers unveiled a review of Sex and Relationship Education in primary and secondary schools.
A panel will examine "the right age to begin teaching what the key messages are and content that young people should receive at each key stage".
The group will make recommendations to the Government later in the year without first consulting the public.
Panel members include representatives from the Family Planning Association, Brook Advisory Centres, HIV charity the Terrence Higgins Trust and the Sex Education Forum.
Critics warned that the review is an attempt to introduce by stealth a more explicit sex education programme for young children.
They fear the panel will rubber-stamp an official report from Government advisers in 2006 which said sex education lessons should on the curriculum in all primary schools.
At present, primary heads and governors decide whether or not to provide sex education and what it should involve beyond the compulsory science requirements laid down in the National Curriculum.
They must have a policy on whether or not they provide sex education.
If they do provide it, parents have the right to withdraw their children.
The 2006 report by the Independent Advisory Group on Teenage Pregnancy and the Independent Advisory Group on Sexual Health and HIV said sex and relationship lessons should be compulsory in all schools.
Norman Wells, director of the pressure-group Family and Youth Concern-said parents must retain the freedom to withdraw their children from sex education lessons "they believe do more harm than good".
He added: "Many of the organisations represented on the Government's steering group share a strong hostility towards teaching children the positive benefits of saving sex for marriage.
"Yet this is a message they desperately need to hear.
"The Government is under great pressure from the sex education establishment to introduce compulsory sex education for all children from the age of five and I'm sure there is a very real danger that this review will conclude that this is what is required."
The Department for Children, Schools and Families said the review was necessary because delivery of Sex and Relationship Education was "patchy". It insisted the panel represented a wide variety of views.
Schools Minister Jim Knight said: "This review is a direct response to concerns raised by young people.
"We know SRE is good in most schools, but we know from talking to young people that in some schools the teaching is not up to scratch. This is not acceptable.
"I want to look at what the best schools are doing and make sure every school follows their lead."
Children's Minister Beverley Hughes added: "Consistent delivery of SRE across England will also help tackle teenage pregnancy in those areas that are still struggling with their rates and where local authorities have not fully implemented tried-and-tested advice." (Daily Mail, 2.25.2008, Sarah Harris) http://www.dailymail.co.uk/news/article-518670/Sex-education-compulsory-year-olds.html