Primary school children should have compulsory sex education lessons, MPs said today.
A cross-party group of MPs is calling on the government to make advice on sexual health and relationships mandatory in all schools.
The group, led by Chris Bryant, a parliamentary aide to Harriet Harman, the Labour deputy leader, says that giving children more information would help reduce teenage pregnancy rates, abortion and sexually transmitted diseases.
The appeal, made in a letter in the Daily Telegraph, says:
"International evidence suggests that high-quality sex and relationship education that puts sex in its proper context, that starts early enough to make a difference and that gives youngsters the confidence and ability to make well informed decisions helps young people delay their first sexual experience and leads to lower teenage pregnancy levels.
"Young people and their parents continually ask for sex and relationships to be taught in schools.
"We call on the government to guarantee appropriate sex and relationship education in every primary and secondary school by putting personal, social and health education on a statutory basis as part of the national curriculum."
Under existing rules, all children must be taught the biological facts of human reproduction but there is no obligation to learn about the social and emotional aspects of sexual behaviour.
The MPs say that must change in the letter, which is also signed by charities, including the Teenage Pregnancy Independent Advisory Group, and the UK Youth Parliament.
The letter states that although rates have fallen over the past 20 years, Britain still has by far the highest rate of teenage pregnancy in Europe.
A report by the UKYP found information about sex education was failing in many schools.
But critics, including the campaign group the Family Education Trust, say there is no evidence that starting sex education at the age of four would reduce teenage pregnancy rates.
The schools minister, Jim Knight, announced a review into sex and relationships education in February.
A spokeswoman for the Department for Children, Schools and Families said: "We have held a review into the delivery and content of sex and relationships education and will report back in due course."
