The Government is to consult on tough new measures to protect children from internet pornography.
Under plans being draw up by Downing Street, it would be up to customers to "opt-in" to receiving adult content online when they take out a broadband contract.
Campaigners have argued it is too easy for children to access explicit adult content on their phones and computers.
Currently, parents who want to ensure their children do not have access to internet pornography must opt out of services.
But under the plans, internet service providers (ISPs) will be forced to ask customers if they wish to access sites when they sign up for broadband.
Mr Cameron is due to meet large ISPs to discuss the measures but he is understood to be against even tougher controls on internet porn.
The industry is worth an estimated £3bn a year but the issue has proved sensitive with Conservative MPs.
Tory backbencher Claire Perry has accused internet companies of being "complicit" in exposing children to pornography.
She said ISPs had been "dragging their feet" on reforming the way explicit material is accessed online.
A report by MPs found 77% of women would sign up to a default filter barring pornographic content.