Ioannis Dekas, 52, is seeking to force the Government to abide by its commitment in the 2017 digital economy act to introduce age verification for porn sites.

This would prevent anyone under 18 from gaining access to the sites without their age being legally verified with companies that failed to do so facing sanctions including fines.

He is arguing that it is difficult to help his sons grow into men who respect women when they have so much access to violent imagery.

He said: “I take responsibility as a parent but porn is harming our young people. There are times they have accessed it despite our efforts to safeguard and protect them.”

Lawyers have begun judicial review proceedings against the government by issuing a pre-action letter to Oliver Dowden, the Culture Secretary.

Age verification for legal pornography sites was introduced under part 3 of the Digital Economy Act in 2017 but the government never enforced it.

Ministers have said the planned online harms bill will instead protect children by placing a burden on internet providers to protect users from “harms” including viewing pornography while under age.

But critics point out that this bill is currently only at white paper stage with no current date to bring it before parliament.

Paul Conrathe, solicitor with Sinclairslaw, is bringing the legal action on the basis that children are being harmed currently by the lack of age verification, in direct breach of the government’s legal duty to protect them.

Conrathe told the Telegraph: “The first point is that it is an abuse of power in preventing part 3 of the Act coming into effect.

“The second point is the obligation under the human rights act to protect children from online harms. There is a lacuna of protection that could last for years.

“We have an acknowledged problem that we could do something about now as a first step but we are doing nothing.

“On any view it is likely to be at least another two years before any new online safety act takes effect, it may be longer.

“Five years is a very long time in the life of a teenager for whom the prevalence of online pornography is having an effect on a daily basis.”

When he was culture secretary, Matt Hancock promised that coming online harms legislation would make the UK “the safest place in the world to be online”.

Another claimant in the judicial review proceedings is Ava Vakil, a student and activist involved in raising the issue of sexual violence among teenagers.

She said: “From my experience looking at sexual violence in schools, young people’s first experience with sex is increasingly pornography that often glorifies extreme violence against women.

“An 11-year-old can’t go to the cinema and watch an 18 film but with more ease, no ticket they can see incredibly harmful material on their phone or a friend’s phone.

“It shouldn’t be bold or controversial to say children should not have complete and unfettered access to violent sexual imagery.”

A survey from City, University of London found that four in five UK 16-and 17-year-olds have seen online pornography – most commonly having watched it on the day of the survey.

The survey of 1,000 16‐ and 17‐year‐olds found that many were watching pornography on social media sites but it was more frequently viewed on pornographic websites.

One of the arguments for not introducing age verification as proposed was because it would not cover social media sites. Dr Neil Thurman who led the survey said the results showed the importance of implementing legislation urgently rather than waiting any longer.

“Young people’s visits to porn sites we found to be surprisingly frequent, with the majority having viewed pornography on the day of the survey.

“Given the frequency with which our research shows dedicated porn websites are viewed by 16-and 17-year-olds, waiting for the online harms bill to come into force certainly carries risks, allowing adolescents to continue to regularly access online content that is problematic in many ways.”