THE government is set to ask medical experts to draw up guidelines on 'safe time limits' for kids using social media.

Health secretary Matt Hancock said he was "very worried" as a father by the growing evidence of the impact of social media on young people's mental health.

He told the Observer he had instructed Dame Sally Davies, the UK's chief medical officer, to begin preparing official guidance on safe time limits that would work in a similar way to safe alcohol limits.

Speaking ahead of the start of the Tory party conference in Birmingham, he told the newspaper: "I am, as a father, very worried about the growing evidence of the impact of social media on children's mental health.

"Unrestricted use (of social media) by younger children risks being very damaging to their mental health.

"So I have asked the chief medical officer to bring forward formal guidance on its use by children."

Some platforms, including Facebook and Instagram, have recently added wellbeing tools that enable users to monitor and restrict their time on the platform.

Mr Hancock hit out at both platforms, which share an owner, over a lack of policing of their rules on age limits.

He said: "The guidelines for WhatsApp say you shouldn't be on it unless you're 16. But again, they don't lift a finger."