It was the summer of 2009 and we were sitting on the shed roof in my friend’s back garden, three young girls talking about sex. “Do you ever feel pressure,” one of my friends asked rather nervously, “to watch porn?” We all went a little quiet at this, we’re girls; we weren’t supposed to talk about porn. But we had felt pressure – not just to watch porn, but at some point, to act out in a relationship what we thought went on in porn.

The past 10 years have seen incredible changes in how people - particularly young people - interact with each other. Mostly, this is brilliant. It’s given millions of people access to information with the touch of a button, or the swipe of a finger across a phone screen.

But more frequently than ever, young people are learning about their bodies, their sexual desires and sexual relationships with others through the internet, whether it’s via porn or from documenting relationships on social networks. In fact, a new Telegraph/ NSPCC poll has found almost a third of young people believe porn dictates how to behave in a relationship.

Effective sex education is essential if my generation is to make responsible and well-informed decisions about the lives we go on to lead.

Current sex and relationship education guidelines, which teachers use to plan lessons, were last updated in 2000 – some 13 years ago – and contain no reference to the internet; mobile technology or online bullying.

I’m calling on the Prime Minister to urgently convene a working group of young people, teachers, professionals and online experts to re-write the guidance to reflect the influence of the internet on how people view sex and relationships.

 I’m working with Telegraph Wonder Women, The Daily Telegraph's women's channel, on this campaign. We need thousands of signatures to show the Government that this is an important issue for everyone.

I understand the Department for Education has had several opportunities to put this right but has failed to act. This is rubbish. Why are they leaving my generation to learn about sex and relationships from online porn and ‘selfies’?

Please sign our petition and tell the Prime Minister to bring sex education into the 21st Century.