Pupils in Wales could take control of their own sex education as part of a drive to tackle teenage pregnancy and halt the spread of sexually transmitted infections.
An action plan to improve sexual health and wellbeing in Wales was launched by the Assembly government this week.
The document says sex and relationship education (SRE) must have a higher profile in secondary schools, with improved guidance and better training for teachers.
But it also says schools must take account of their pupils' views on what content they need at different stages of their education.
Estyn, the Welsh inspectorate, has previously highlighted pupils' lack of involvement in planning their sex education as a key reason why provision is poor in many areas. And the government proposal has been backed by Olwen Williams, one of Wales's leading experts in sexual health.
Dr Williams told TES Cymru: "There's evidence that peer-led education can be extremely effective in delivering sex education, especially concerning relationships and sexually transmitted infections (STIs). A few schools have gone down that path very successfully."
But David Evans, secretary of the NUT Cymru union, said teachers must remain in control of sex education. "It's good to listen to pupils, but with such a delicate subject, that has to be gauged by their age and general understanding of the issues involved," he said.
A 2007 Estyn report found only a minority of schools were delivering good- quality sex education. Updated guidance will be published in September next year, and teachers will be given specialist training from January 2011.
Dr Williams said staff teaching sex education must be given "in-depth knowledge" of the subject.
"There are some excellent examples of good SRE, then there are other schools that only pay it lip service," she said. "We are no longer seeing young people who know nothing about STIs or contraception, so the education seems to be happening. But it's about what they do with that knowledge."
Mr Evans said many teachers would be prepared to undergo the training, but they should not be forced into teaching sex education if they felt uncomfortable with it.
Under the proposals, more outside organisations will be brought in to help deliver sex education. It is also expected that the family nurses promised for every secondary by 2011 will play a key role.
The document also says schools need to do more to inform parents about what their children are being taught about sex at each key stage.
"Parents can supplement this with discussion at home and are reassured that good SRE will give their children the knowledge, skills and confidence to make informed, safe choices," it says.
Dr Williams said parents must be involved. She called for sex education to be strengthened in primary schools. The document makes no recommendations about primary-level sex education, but notes that the government recommends all primaries have a "graduated, age-appropriate SRE programme".
It also proposes more bilingual sex education resources for schools and online resources for parents.
The latest Assembly government figures show the number of teen pregnancies in Wales is rising and remains higher than in England.
Wrexham has the highest rate in Wales, with 61.3 conceptions for every 1,000 females aged 15-17, while Monmouthshire has the lowest at 28.6 per 1,000.
The draft document, Sexual Health and Wellbeing for Wales 2009-2014, will go out to consultation for four months.
Edwina Hart, the health minister, said: "A key component of this new document is the importance of educating people about the need for a greater awareness of good sexual health and the dangers associated with unprotected sex."