A government source said the decision to lower the minimum age for WhatsApp access “flies in the face of growing concerns from parents about children’s social media use and rising adolescent mental ill-health”.

“Policymakers will rightly ask what evidence Meta has to prove it’s safe for 14 year olds to access encrypted WhatsApp groups and what protections they’re putting in place to empower parents to keep their kids safe.”

Prime Minister Rishi Sunak told the BBC that, as a father of two children, he believed it was “imperative that we keep them safe online”.

He said the Online Safety Act was “one of the first anywhere in the world” and would be a step towards that goal.

“What it does is give the regulator really tough new powers to make sure that the big social media companies are protecting our children from this type of material,” he said.

“They shouldn’t be seeing it – particularly things like self-harm – and if they don’t comply with the guidelines that the regulator puts down, there will be in for very significant fines.

“We want our kids to be growing up safely – out playing in fields, or online.”