Media Watch UK is asking people to make their concerns about internet pornography known as the House of Lords considers new legislation to protect children.
The Online Safety Bill is making its way through Parliament and had its first reading in the House of Lords last week. It will have a second reading later in 2013.
If the bill is passed into law, it will require Internet Service Providers (ISPs) and mobile phone operators to provide an internet service without access to pornography as the default setting. Adult subscribers would have to opt-in to access such material.
The service providers would also have to make online safety information available to subscribers.
The SafeOnline website has been set up to let people have their say about the best way of protecting children from harmful online content.
Media Watch UK is encouraging people to use the website to contact members of the House of Lords to ask them to support the bill and press for an early second reading.
"This is an opportunity for everyone to have their say. It is an important step towards seeing online pornography 'switched off'," the group said.
"The impact of online sexual content on children is of great concern. Research suggests that as many as one in three under-tens have seen online pornography and only 3% of pornographic websites require proof of age before granting access to sexually explicit material.
"For many of today's children, their first introduction to the adult world of sex and sexuality is pornography; a very poor sex educator. This exposure will inevitably shape their sexual lives and affect future relationships."