The ban being considered will only apply to those who cannot vote, because they are under the age of 16. Ministers cite polls that show significant public support for such a curb. The government issued guidance on the use of mobile phones in English schools two months ago, but other curbs are said to have been considered to better protect children after a few campaigns.

A March survey by Parentkind of 2,496 parents of school-age children in England found that 58 per cent of parents believe the government should ban smartphones for under-16s. More than four in five parents said they felt smartphones were "harmful" to children and young people.

Another survey by More in Common revealed that 64 per cent of people thought that a ban on selling smartphones to under-16s would be a good idea, compared with 20 per cent who said it was a bad idea.

The curb was famous among 2019 Tory voters, according to the thinktank, which found 72 per cent backed a ban, as did 61 per cent of Labour voters. But the thought of another ban has left some Conservatives uneasy.

One Tory government source described the idea as "out of touch," noting: "It's not the government's role to step in and microparent; we're meant to make parents more aware of the powers they have like restrictions on websites, apps and even the use of parental control apps." They said only in extreme cases could the government "parent better than actual parents and guardians."