Government wants sex education at age of seven

Youngsters aged 11 should also be given lessons on the importance of marriage and teenagers taught about parenting.

The new guide for schools in England contains advice to teachers on how to teach sex and relationships. It is the first time the advice has been updated since 2000 but has immediately drawn criticism.

Personal, social, health and economic education (PSHE) will be mandatory in both primary and secondary schools from September 2011, with parents losing their right to withdraw their child from sex education lessons once they turn 15.

Norman Wells, of the Family Education Trust, said the new guidance would confirm the fears of many parents.

"Contrary to the Government's claims, introducing sex education at an early age runs the risk of breaking down children's natural sense of reserve, " he said. "Far from being a hindrance, children's natural inhibitions and sense of modesty in talking about sexual matters are healthy and provide a necessary safeguard against both sexual abuse and casual attitudes towards sexual intimacy later on."

The proposals, which are being put out to consultation, say 11 to 14-year-olds should learn about "the nature and importance of marriage and of stable relationships for family life and bringing up children".

And the guide suggests pupils should be encouraged to discuss the "myths" they hear about sex and growing up from their friends.

It says children as young as 14 should be given lessons on parenting, and asked questions such as "What are the responsibilities of being a parent and what skills do I need?"

It covers sex and relationship education for five to 16-year-olds, with recommendations teachers ask children as young as five to think about questions such as "Where do babies come from?" and "What are the differences between girls' and boys' bodies?"

From the age of seven, youngsters should be taught about the basics of reproduction.

The guidance has been drafted by a group including teachers, health charities, faith groups and young people and suggests teachers should talk to teenagers about resisting pressures to have sex too early because they can feel pressurised by sexual images in the media and on mobile phones.

School Secretary Ed Balls, the MP for Normanton in West Yorkshire, said: "New technologies and a 24-hour media mean that young people are increasingly exposed to images and content that can make them feel pressure to be sexually active before they are ready and can give them misleading information about relationships and growing up.

"We want to give young people the facts so that they can stay safe and healthy.

"We also want young people to understand the importance of marriage and other stable relationships – these are the bedrock of family life."