Technology companies such as Apple and Google have been told to block access to naked images on smartphones and tablets for under-18s.

Speaking at London Tech Week, the prime minister Sir Keir Starmer said that tech companies must activate built-in features or implement technical solutions on smartphones and tablets to detect and block nude images for children

Tech companies were warned that if they 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.

Prime Minister Keir Starmer said: "This is not an impossible challenge – these are some of the most innovative companies in the world. But if they choose not to, then we will act and change the law.

"The changes will apply to UK devices, including both existing and newly sold smartphones and tablets. Legislation could cover operating system providers and others in the supply chain, such as retailers, and will not affect the use of devices owned and used by adults who verify their age."

Apple recently introduced age checks for iPhone users, making it the first company to activate safety features by default for those who are not verified as over 18.

Despite this, the nudity detection is not applied to the camera or broader apps, third-party messaging services, or search functions, meaning children can still take, view, share and save nude images. The government therefore wants Apple and Google to block nudity across the whole device by default, so they can only be deactivated via age assurance.