Adults who want to view pornographic websites will be able to buy a code at newsagents to prove they are over 18 when new age verification laws are introduced later this year.

A 16-digit code - or “porn pass” - will be one option available to the estimated 25 million Britons who regularly visit adult websites and so will be required to prove they are not under age.

The move, part of new legislation being drawn up, is an attempt by the Government to prevent children accessing obscene online material.

New rules were due to come into force in April, but the Government pushed back the date in an attempt to ensure any system introduced was workable.

The British Board of Film Classification (BBFC), the country’s film censor, has conducted a public consultation about ways to enforce a proof of age process after it was appointed by ministers to enforce the new rules.