Porn sites which fail to stop children accessing them may be forced to introduce age verification, the Children's Commissioner for England has warned.
It comes after Dame Rachel de Souza revealed she is calling for 'stronger protections' to be imposed to keep children safe online.
She has also proposed three alternative legislative measures for the Government to consider if tech companies are unable to effectively fix the problem of children seeing adult content online.
The first is reinstating the proposed 2017 law on age verification for porn sites and instructing Ofcom to produce a code of practice for social media firms.
Dame Rachel also suggested fast-track new legislation in the autumn, requiring commercial porn sites to verify ages and to create a voluntary code of practice for social media companies.
Dame Rachel de Souza has announced she is calling for 'stronger protections' to be imposed to keep children safe online
The final suggestion is for the Government to back a Private Member's Bill which would lay out minimum standards for social media firms to check the ages of users - requiring others to adopt this as well.
Dame Rachel told the Telegraph: 'We've got to put stronger protections in place.
'Despite all the best efforts of the tech companies trying to clean sites up, it just clearly isn't as effective as it needs to be.
'These tech companies are so huge.
'They are such strong businesses, I really want to push back on them and say "Although you are doing many things, the volume of traffic is so huge, you need to do more to keep kids safe".'
Dame Rachel said she is meeting bosses from social media firms this week 'to challenge them to grasp this nettle of keeping children safe and keeping children who should not be on their sites off their sites and getting unsuitable material off their sites'.
The idea of implementing age checks on pornography websites, and fining those sites that don't comply, has existed for several years now (file photo)
It comes after an online study last month, co-conducted by Dame Rachel, showed social media accounts linked to children are 'directly targeted' with graphic content within as little as 24 hours of being created.
The report showed that, despite knowing the age of younger users, social media platforms were allowing them to be contacted, unsolicited, by adults, as well as recommending potentially damaging content.
The idea of implementing age checks on pornography websites, and fining those sites that don't comply, has existed for several years now.
Back in 2016, the UK government launched a public consultation over plans to implement age checks on pornography sites.
It was then included in the Digital Economy Act 2017 – but the provision was delayed and eventually abandoned in October 2019.
