A petition signed by more than 110,000 people demanding internet companies block access to hardcore pornography as a default setting to protect children is being handed to the Government.
Peers, MPs and church figures are among those who have signed the Safetynet petition demanding internet service providers (ISPs) be made to compulsorily block access to pornography on computers, mobile phones and tablets, organiser Premier Christian Media (PCM) said.
The petition, written as a letter to Jeremy Hunt, the Secretary of State for Culture, Media and Sport, claims one in three 10-year-olds has "stumbled upon pornography online" and that youths aged 12 to 17 are the largest consumers of internet porn.
It will be handed in to 10 Downing Street by Safetynet representatives and a cross-party group of MPs, organisers said, with a second copy being sent to the Department for Education (DfE).
Peter Kerridge, the chief executive of PCM, said: "This simple measure would in no way restrict adults from accessing such websites by specific application but would help to protect generations of young people from online pornographers."
In June the Government launched a 10-week consultation asking parents and businesses for their views on the best way to shield children from internet pornography.
The study is also looking at measures to protect children from other potentially harmful sites such as those which promote suicide, anorexia, gambling, self-harm and violence. Views on preventing online sexual grooming and cyber-bullying are also being sought, the DfE said when it was launched.
Parents are being asked for their views on three possible systems, including one where users have to "opt in" to see adult sites, and one in which customers are presented with an unavoidable choice about whether they want filters and blocks installed.
The third option would combine the two systems, enabling customers to block some content automatically and be given a choice to unblock them as they wish.
It comes after David Cameron said earlier this year that the Government needed to look at whether internet services or devices might come with a filter on as their default setting or have a combination of a filter and an "active choice" by the customer.