Children are stumbling upon pornography online from as young as seven, a report has indicated.
The survey, from the British Board of Film Classification (BBFC), suggested three-quarters of parents felt their child would not have seen porn online but more than half had done so.
Youngsters under the age of 10 described feeling “grossed out” and “confused” by what they had seen.
The UK is trying to make it harder for children to see adult content.
It is bringing in a new regime of age verification, under which websites hosting mainly pornography will be required to stop UK users from accessing content unless they can prove they are over 18.
Every time a UK IP address attempts to access a pornography website, the user will be required to verify their age.
The plans, part of the Digital Economy Act, were due to come into force in July but have since been delayed for a further six months.
The BBFC has been appointed as the age-verification regulator and will monitor adult sites to ensure they have appropriate means of checking the age of visitors.