“I’ve not met anybody within these companies that thinks it is appropriate or that allows their own children to use these products under the age of 13. So we should be working together to solve this issue.”

‘Partnering with parents’

Asked if that meant the 60% of 8 to 12-year-olds with social media accounts should be thrown off, he said: “I would expect them to be removed and for the law to be rigorously enforced”.

“It’s going to be really hard for kids who have access that will now have it taken away. It is tough, but we’re on the side of parents here.

“Parents repeatedly tell me that once they’re on [social media], it is a constant battle between parent and child to get it out of their hands, particularly interrupting study time, bedtime, and family time. So we are now partnering with parents, giving them the baseline to move forward.”

The tech firms have been told they must either ensure their minimum age limits of 13 are properly enforced, or radically overhaul their sites to make content safe enough for the tens of thousands of under-age children currently using them.

The measures are part of new children’s codes set in Britain by the regulator Ofcom, which require companies to block their access to harmful content, including suicide, self-harm, violence, or misogyny, from July 25.

From Friday, firms hosting porn will also be required by law to introduce “highly effective” age checks such as credit cards, photo ID matching and digital ID services to prevent any under-18s accessing their sites.

The top 10 adult websites, which account for 40% of porn site users, have signed up to these age checks with over 6000 other sites including Elon Musk’s X, Grindr, and Reddit.

Those that fail to implement age checks at the ages of 13 and 18 will face fines of up to 10% of their global turnover or be banned from operating in the UK.

Kyle said Ofcom must not hesitate to use its powers, including blocking sites to “send the message that access to the British economy and society is a privilege, not a right”.

At least half a dozen tech firms, including a suicide forum and micro-blogging site, have already withdrawn from the UK market by geo-blocking users rather than comply with the Online Safety Act.

The changes on Friday follow the implementation in March of tougher bans on illegal online content including child sex abuse, terrorism, and fraud.

However, Ofcom’s new powers are considered more significant for protecting children from “legal” harms such as suicide and self-harm content, which are blamed for 14-year-old Molly Russell taking her own life.

Kyle said the move represented the “biggest step change in the experience of young people online since the internet was created”.

It also marks the culmination of an eight-year campaign by the Telegraph for a statutory duty of care on tech giants to protect children from online harms.

On behalf of the Government, he offered an apology: “My other reflection is the huge apology we owe young people who are over the age of 13 and yet lived in the online smartphone era.

“They were unprotected from the vile, harmful, and damaging forces that made their way into their feeds without any restraint. I and we as a society owe them an apology, and I certainly offer it with all sincerity.”

Kyle said the changes would mean tech bosses, who can face up to two years in jail under the laws for persistent breaches of regulations, would “live in anxiety” rather than the children who have previously been fed “harmful content”.

“It means that people who peddle harmful and criminal content will finally be the people who live in anxiety, because we can and we will come after them if they continue to peddle their content,” said Kyle.

“I expect the law to be enforced to the full extent of the powers that Parliament has granted.”

He also warned there would be tough penalties for tech firms that tried to circumvent the new laws with, for example, Virtual Private Networks (VPNs) where users can disguise their IDs and bypass blocks on content.

“If platforms or sites signpost towards workarounds like VPNs, then that itself is a crime and will be tackled by these codes,” said Kyle.

“If a company directly delivers harmful content into the feeds of children, it is the arrival into their feeds which is the offence. If they direct children via other means to that content, it has the same outcome.”

He confirmed the Government was considering further measures to combat the “addictive” nature of social media by introducing two-hour caps on app time and curfews to limit use before bedtime. They are expected to be unveiled in the autumn.

“In the offline world, parents set boundaries on diet, exercise, social networks and sleep time but we’ve never had that conversation about the online world. It’s time we did,” said Kyle.

He added: “It is not telling parents how to parent, but offering tools to parents to set the kind of family life that they think appropriate.”

Kyle revealed that at every meeting with tech bosses, he imagined there was a camera in the room where parents like Molly Russell’s father who lost their children in online tragedies could watch him.

“Would they feel their views and their children’s experiences had been represented? I hope that they would,” he said.

“Some of those conversations I’ve had have been uncomfortable and ended uncomfortably.”

He said that was the reason why he was aiming for all harmful content to be removed from children’s feeds.

“I’m aiming for 100% but I need to be realistic with people,” he said.

“If we take steps forward where 70, 80, or even more per cent of vile, hateful, damaging content disappears from children’s feeds, that’s a win that I’ll take to the bank and move forward from.

“But these companies have the capacity to allow hundreds of millions, if not billions, of posts to go online rapidly. Don’t tell me they don’t have the infrastructure that enables it to be removed too.

“This Act has been one of the longest pieces of legislation in gestation, in its passage through Parliament and its pathway to implementation, than any other. They have had time. They have seen the direction of travel. Now it’s time to act.”