The UK could become the first country in the world where children would be blocked from taking, sharing, or viewing naked images on their phones and tablets, under plans announced by the government.
Speaking at London Tech Week on Monday, Prime Minister Keir Starmer called on technology companies to introduce controls that would prevent children from sending or receiving sexually explicit images.
The Home Office said in a statement the proposals would make Britain "the first country in the world where it is impossible for children to take, share or view naked pictures on their devices."
Under the plans, tech companies including market leaders Apple and Google would be required to activate existing safety features or develop new technical solutions to detect and block nude images for children.
The Home Office said: "Under new plans, Big Tech companies like Apple and Google must activate built-in features or implement technical solutions on smartphones and tablets to detect and block nude images for children.
"This will prevent predators from being able to exploit and abuse victims through their devices, as well as stopping children from being able to access pornography. Adults will still be able to take, share or view nude content through an age verification process."
The government said technology firms would have three months to act voluntarily. If they fail to do so, ministers say legislation could follow, including financial penalties.
The Home Office said: "Now is the time for tech companies to step up and work with government to solve this horrific issue. If companies do not act within three months, the government will bring forward legislation to force them to activate the technology. This will include fines for companies. Nothing is off the table, and as a last resort we are exploring criminal liability for tech bosses who fail to comply."
In his speech, Starmer said the issue of children sharing explicit images online could no longer be accepted as an unavoidable consequence of modern technology.
"One issue is the ability for children with phones to send and receive nude images," he said. "For too long, people have been told that is simply the price of modern tech, that nothing can be done, that government is powerless, that parents just have to accept it."
"I reject that completely, because tech should adapt to the needs of society, not the other way around. That is why today I am calling on tech companies operating in this country to introduce device controls that prevent children from sending and receiving sexually explicit images," he said.