"I've brought some goody bags this week, but they don't just contain sweets," says Vivienne Quant, rustling white paper packets tantalisingly at a group of women sitting in a South London classroom. Everyone takes a bag and examines its contents: a large chocolate coin, a fact file - and an array of contraceptives.

Without pausing for breath, Quant guides the session on. "This week we're looking at contraception," she explains. "What it is, the advantage or disadvantage of each method and their efficiency. We'll find out what you know about the seven methods we'll review, and discuss what is most suited to young people."

Each mother reveals the contents of her package and contemplates the options: contraceptive pills, intra-uterine devices, an implant, hormone patch, diaphragm, fertility indicator, flavoured and plain male condoms, two plastic penises, a female condom, and a contraceptive injection - with some expressing surprise at the range available.

The atmosphere may be informal at this two-hour Speakeasy session - which is held at Jessop Primary School in Herne Hill and is being run by sexual health charity fpa - but the level of concentration suggests this is a serious issue for these parents. Each mother shows her contraceptive and reads the enclosed fact sheet. One shows how to correctly put a condom on a plastic penis, while everyone checks which part of the assessment sheet to complete showing evidence of learning.

They comment on their suitability for teenagers, the protection offered from sexually transmitted infections (STIs), and whether a young person would use them. The subject matter is emotive, triggering difficult memories - as they share experiences some are tearful, some shy.

Breaking the cycle of silence

Sarah Waterton, mother of six-year-old Anna, and Barbara Barsanti - mum to Francesca, 16, Hayden, seven, and Andrea, six - confide that sex was taboo in their Italian families. They feel this course helps them to break the pattern for their children.

"I never got any sex education and it was hard," admits Barbara who had her first child aged 19. "I was scared to tell my parents I was pregnant and when I did they cried. I wanted things to be different with my daughter so I have a very open relationship with her. We talk about sex and her friends ask me about it too."

"I wanted to try to protect my daughter from getting pregnant early, or catching STIs. I wanted to empower her," Sarah adds. "Coming from an Italian family and living here I felt it was important to be able to talk to my daughter honestly."

Pamela Martin, mother of seven-year-old Suillehain, agrees. "I come from Jamaica where my parents never discussed sex, so for me to be able to talk to my son about it openly is a big deal. It is a fact of life he has to know."

These instincts reflect Dutch research, which is cited by Parentline Plus and which shows young people whose families talk about sex are more likely to delay the age at which they first have intercourse and are more likely to use contraception. It also reveals that young people would prefer to talk to their parents about sex and, if communication begins early about making sexual decisions, the child is more likely to approach their parent than rely on misinformation from peers.

As a result, the Speakeasy course aims to equip parents with the information and confidence to talk about sex and relationship issues with their children in an imaginative and age-appropriate way - using fpa literature, books by children's author Babette Cole, and a variety of other resources.

Feedback from this group indicates it is pitched correctly.

A community-based education scheme run by the fpa since 2002 with funding from the Big Lottery Fund and the Government's Parenting Fund, the training targets families particularly in areas of social and economic disadvantage.

Its relevance has never been greater because, despite a £138m Government-led campaign, the UK has the highest teenage pregnancy rates in Europe, and the London borough of Lambeth - where this Speakeasy course is running - has the highest rates in England.

While Gill Frances, vice-chair of the Independent Advisory Group on Teenage Pregnancy, believes there is clear evidence in the majority of areas that the strategy is working, she admits that challenges remain, especially in applying what has been learned to predominantly urban areas with high levels of deprivation and mobility, and where it is difficult to sustain effective programmes.

In fact, campaigners, including the sexual health charity Brook and fpa, are calling for mandatory sex and relationship education (SRE) from primary school upwards. The final report of the Teenage Pregnancy Strategy Evaluation 2005 supports these views: "SRE is often received too late. Its status and quality could be improved by making high-quality personal, social and health education mandatory within the National Curriculum." Yet the Department for Education and Skills has no plans to change SRE's discretionary position in school timetables.

Delivery remains patchy due to a variety of issues, according to Anna Martinez, co-ordinator at the Sex Education Forum. "In some schools, there are not enough trained teachers," she explains. "It can also be down to worries about parental concerns."

According to Jan Fry, director of external relations at Parentline Plus, greater interaction between schools and parents is crucial so parents feel they understand what is happening at school.

A burgeoning success

Meanwhile, Speakeasy's popularity is burgeoning. For Quant, a former midwife with 32 years' experience, the last three years have been very rewarding: "I came out of retirement to do this and it's been worthwhile because there is so much demand."

One of the benefits of the course is its ability to bridge diversity.

Groups are needs-led to cater for parents with little or no education and those from different backgrounds: "We do not want to peddle a permissive agenda," explains David Kesterton, Speakeasy's project manager. "We want parents to take this on in the context of their own culture.

"For instance, if working with Muslim parents we may take some words out to avoid offence. We thought there may be some reticence but we had a group of Muslim mothers who opened up and gained information and communication skills for themselves and their children."

In addition, Kesterton tells of Somali, Afghan, Turkish, Vietnamese and Bangladeshi parents who've completed the training helped by translators.

"We've also helped foster carers and worked with specialist agencies including the Liverpool Autistic Spectrum Disorder Society," he says.

Addressing sex informally

Starting with a taster session in which parents reveal their sources of information and the myths they've learned about sex, each subsequent two-hour session addresses a range of topics approached through informally structured group activities. This includes working with poster-sized pictures of a girl and boy, drawing in changes at puberty, exploring what children need to know, and how to give age-appropriate information. STIs are discussed using a quiz, jigsaw and colour photographs.

A later session focuses on child protection, often raising the spectre of difficult childhood experiences for parents. "We tread a tightrope with this," admits Kesterton. "There is quite a lot of information sharing on Speakeasy but we have to be clear its purpose is not to be a therapy group and signpost parents to more appropriate services."

For many, it's also an opportunity to be involved in adult education for the first time. After completing the course, parents are eligible for an open accreditation award at Level Two - which shows learning equivalent to GCSE-level A to C.

Mothers at Jessop Primary feel the training is already helping them.

Lavinia Cunningham believes it's made it easier to talk to her sons Corey, eight, and Calvin, five. "My son asked if I had a penis or a vagina and I was able to talk to him without getting embarrassed and explain the difference between boys and girls," she reveals. "He said he liked having a penis more and we laughed about that."

"Perhaps he might like one of these," says Quant, passing her a reference book Let's Talk About Sex. Lavinia scans the copy cautiously saying: "There's a lot of information. I'll read it myself first."

CASE STUDY - How Parentline Plus is teaching parents to talk to their children

"It's important that we look at this issue in the round. We must look at preventative communication early on and build upon it," says Jan Fry, director of external relations at Parentline Plus.

The national charity recently unveiled a guide for parents entitled The Real Picture. Part of its Time to Talk campaign, it aims to create greater openness between teenagers and parents.

Citing the system of early sex and relationship education in schools in Holland, which places the emphasis upon responsibility and respecting the individual, Fry has no doubts this approach makes a huge difference.

"Where children talk honestly and openly with their parents about the whole gamut of relationships they're more likely to delay having early sex and use protection," she says. "Though UK teenage pregnancy rates are the highest in Europe, it is crucial parents are not made to feel failures. They tell us they're worried about risky behaviour, drugs and alcohol abuse and they want to be able to talk to their children."

As a result, Parentline Plus is encouraging parents to talk to their teenagers about sex and relationship issues. Its leaflet, distributed in GP surgeries, is also available via its free helpline and on the internet.

It gives information, tips and useful contacts to parents anxious about the risks their children may be taking and struggling to come to terms with experiences different from their own.

Respect teenagers' privacy

For instance, it suggests that parents should keep an open mind and listen to their children's views, set boundaries but be aware when to let go, and understand that their children may be moody, aggressive or angry because they cannot put their feelings into words.

Finally, they should try to remember what it was like to be a teenager and avoid being nosey. "Build up trust and respect their privacy and teenagers will tell you more," says Fry.

FACT FILE

- 3,000 parents and carers have attended Speakeasy courses, while 250 professionals have been trained or are in training to run courses

- More than 75 per cent of parents increased their knowledge of contraception, puberty and STIs, while 52 per cent said they knew more about keeping children safe

- Over 85 per cent of participants gained an open accreditation award and 13 per cent explored further education as a result of the course. One third found accreditation helpful to move into training or work.