David Cameron has welcomed the launch of a new multimillion-pound information campaign by the UK's largest broadband providers to help families stay safe online.
BT, Sky, TalkTalk and Virgin Media are supporting the drive to raise awareness of how to tackle issues including cyber-bullying and access to adult content on the internet.
Aimed at parents, it is intended to encourage and support them in talking to their children about how they can stay safe when surfing the net.
The nationwide campaign will provide information about whole-home and device-level parental controls, in order to help people make the most appropriate choices for their household.
The announcement comes as the Prime Minister is set to host a meeting with industry representatives in Downing Street on Monday.
No 10 said Sky and TalkTalk were now installing "family friendly" internet filters that will be automatically switched on for all new broadband account holders, with Virgin and BT set to follow in the next two months.
Homes with an existing internet connection will be required to choose whether to switch on a filter by the end of next year.
Mr Cameron said: "In the weeks and months ahead, millions of hardworking families will only need one click to protect their whole home and to keep their children safe.
"And when someone sets up a new broadband account, the settings to install family friendly filters will be automatically selected and it will only be switched off if a parent chooses to do so.
"As a dad, it is very simple: I want to know my children are protected when they go on to the internet. A family friendly filter gives me the tool to do that and so this is a really important step forward by the internet service providers.
"We all need to work together, both to prevent children from accessing pornography and educate them about keeping safe online, and I will continue to ensure this happens."
The broadband companies said they would be supporting the new information campaign for a minimum of three years, and will be forming a new joint venture to lead the campaign.
The cost of next year's marketing and advertising alone will be in excess of £25 million.
Research conducted for the campaign found that while more than four out of five (83%) parents have talked to their children about how to stay safe online, nearly as many again (81%) are unsure where to go to get good advice.
The campaign will guide parents to expert help and recommendations about how to stay safe on the web.
Virgin Media chief executive Tom Mockridge said: "Being online opens up huge opportunities for us all and we believe technology helps make good things happen.
"But there are also questions and challenges we need to tackle and, with significant support from across the broadband industry, this nationwide campaign will help ensure all our customers make the most of the parental controls, tools and information we provide to help them stay safe online."
TalkTalk chief executive Dido Harding said: "This is a major step forward for internet safety in the UK, with the four leading internet providers coming together to lead the way."
BT chief executive Gavin Patterson said: "We are very pleased to be a part of this joint effort across the broadband industry to help families to get the best advice and support about online safety."
Sky chief executive Jeremy Darroch said: "We are pleased to be supporting this industry-wide initiative to help families enjoy the best of the internet in a safe and secure environment."