Ministers are under renewed pressure to make sex education compulsory, after a pop star accused them of failing young women by not cracking down on sexting in schools.
The charge came from singer and former Girls Aloud star Nicola Roberts - now an ambassador for children's charity Barnardo's. She says she has heard many "heartbreaking" stories of girls who have fallen victim to online predators.
While children are warned not to talk to strangers online, the pressures they face from classmates to send naked pictures is often ignored, Ms Roberts claimed.
"Sexting and child sexual exploitation are serious problems that David Cameron and his government are simply not addressing," the 30-year-old said.
'Show some common sense'
"It infuriates me to see the prime minister treat this issue with such a lack of common sense," Ms Roberts added.
"And I don't understand why the education secretary, Nicky Morgan, isn't publicly backing this change to the status of PSHE lessons.
"I've read lots of social media posts from Ms Morgan in which she tries to empower women. And yet she won't fight for an education that keeps women and girls safe."
Ms Morgan said: "We want young people to be able to take advantage of the vast potential that the internet and social media offers to their lives and education. But we also want to make sure they are aware of the risks and dangers – including sending inappropriate images.
"That's why schools have a responsibility to make sure children know how to stay safe online and when using technology and social media.
"Good schools are already doing this well and, building on their work, we're asking all schools to put in place stronger measures protecting children from harm online – including cyber bullying, pornography and the risk of radicalisation. The law is also crystal clear that where teachers find indecent images of children they must report this to the police.
"Alongside this, all schools should deliver high-quality PSHE, which is an important opportunity to teach young people about how to stay safe and avoid risks. To support schools to do that we have funded and produced a range of guidance and support on issues ranging from consent to internet safety."