Bridget Phillipson is to begin in-depth scrutiny of smartphone bans in schools in England as pressure grows from MPs to act on the effect of social media on teenagers.

The education secretary is to start monitoring a group of schools to understand the effectiveness of the guidance. The education department will also, for the first time, do an in-depth analysis of the national behaviour survey in schools to look at the most successful ways of policing the bans, and the challenges schools are facing.

The guidance states that “all schools should prohibit the use of mobile phones throughout the school day – not only during lessons but break and lunchtimes as well”, but does not say how schools should enforce the bans.

Phillipson is understood to have become frustrated that there is no monitoring of whether the guidance is being followed or proving useful to schools. There are no plans for the government to legislate to ban phones in schools, which ministers believe is fraught with problems.

The monitoring will look at how well schools are following policies, how many schools have bans in place, how schools implement bans, such as keeping phones in lockers or bags, and what impact it is having on behaviour. Specific further questions on smartphones will be added to future national behaviour surveys to gain additional insights.

A government source said: “It beggars belief that the Tories repeatedly told voters they were banning phones but did nothing to ensure the guidance was being followed.

“While the vast majority of schools are complying with the guidance we need to make sure it’s being followed to the letter. Rather than indulge in gimmicks and headline grabbing after years of telling us the guidance was sufficient like the Tories, we’re going to keep schools honest and ensure classrooms and corridors are phone-free.”

In the Commons on Wednesday, Keir Starmer said he had been watching the Netflix drama Adolescence with his teenage children.

The series focuses on a family and their teenage son who is arrested for killing a female classmate, and on the impact of online misogynist influencers. The Labour MP Anneliese Midgley asked the prime minister to do more to tackle online male radicalisation.

The series’ writer Jack Thorne has called for screenings in parliament and said he believes there should be further social media restrictions for young teenagers.

Cabinet ministers are split over whether there is a need to do more on the issue.

MPs who backed a bill from Labour’s Josh MacAlister this year, which would have restricted social media algorithms trained on young teens, said the technology secretary, Peter Kyle, was broadly against any wider changes that would go further than self-policing.

Phillipson’s department only has jurisdiction over school use of smartphones. The health secretary, Wes Streeting, is among those open to more robust action because of the mental health effects of social media, which affect his department.

Speaking to the BBC’s Sunday with Laura Kuenssberg, the shadow education secretary, Laura Trott, said ending phone use in schools was a “no-brainer”.

Trott admitted the guidance issued by the Conservative government last year “hasn’t worked”, with too many children still using phones in classrooms.

The Conservatives put down an amendment to the schools bill earlier this week, asking for a full ban on smartphones in schools, which was voted down by the government. Trott denied the amendment was a “gimmick”, saying “parents, teachers, children are all asking for this”.

According to an Ipsos poll in September 2024, almost half the UK public believe there should be a total ban on smartphones in schools. A majority of parents said their child’s school did not currently have a full ban in place.

MacAlister’s bill included plans to give headteachers legal backing to make schools phone-free.

The bill was watered down to gain government assurances on some of the measures, taking out any requirements on tech companies or schools, and just committing the government to do more research.

Kit Malthouse, a Tory former education secretary, told the House of Commons the watering down amounted to the “gutting of what could have been a landmark bill”.