Sex education is to become compulsory in all primary and secondary schools, but parents will retain the right to withdraw their children from lessons.
The new personal, social, health and economic education curriculum aims to ensure pupils' emotional and sexual health by teaching them that relationship skills have to be learnt and practised.
The lessons, which will become an obligatory part of the national curriculum in all schools from September 2011, cover topics such as personal hygiene, substance abuse and healthy eating. They will also look at same-sex and inter-racial relationships, addressing the benefits of marriage and civil partnerships.
Many organisations have welcomed the announcement. Gill Frances, chair of the independent advisory group on teen pregnancy, said: "It's absolutely critical that the Government now implements this as quickly as possible. We can't afford to have another generation of young people leaving school without this vital knowledge for life."
The new curriculum will be taught throughout the maintained sector, including faith schools. And Julie Bentley, chief executive of the Family Planning Association, hopes parents' right to withdraw children from the class will be reconsidered.
"We're concerned that sex and relationships education will be the only subject in a statutory curriculum where parents have the right to remove their children," she said.
She fears some schools will use the lessons to teach pupils that contraception and abortion are wrong.
"Religion and sex education are not incompatible," she said. "We would like further assurances that all schools will teach it responsibly, ethically and factually."
The Government has also recommended that secondary pupils should learn how to choose a career and manage their money wisely.
Mike Harris, of the Institute of Directors, said: "It seems whenever we have an issue to address - climate change, obesity, financial literacy - we always reach for the national curriculum. These are worthy issues, but can you not do a lot of this within existing subjects?
"I don't think this is going to prevent another financial crisis."
WHAT PUPILS WILL LEARN ABOUT SEX AND RELATIONSHIPS AT EACH STAGE Key Stage 1
- Simple physical changes to the body
- Exercise and healthy eating
- How substances can help or harm the body
- Managing personal hygiene
Key stage 2
- Physical and emotional changes at puberty, and how these relate to human reproduction
- Managing strong or changing emotions
- New relationships that may develop
- Making informed choices about medicines, alcohol and drugs
Key stage 3
- Values in society
- Sexual activity including contraception, pregnancy and sexually transmitted infections
- Different types of relationship, including same-sex partners
- Challenging discrimination
- Laws around drugs, alcohol and tobacco
- Basic first aid
Key stage 4
- Media portrayal of young people, body image and health
- Mental and emotional disorders
- Choices related to sex and substance use
- Characteristics of positive relationships
- Parenting skills
- Impact of separation, divorce and bereavement.