One of England's largest school academy trusts is set to ban phones during the school day.
Ormiston Academies Trust confirmed to the BBC it was phasing out access to smartphones for around 35,000 pupils at its 42 state schools across the country.
Tom Rees, Ormiston's chief executive, told the Guardian that smartphones had disrupted students' learning and wellbeing, adding that there was a "clear correlation" between phone use and concerns about mental health.
Earlier this year, the Department for Education under the previous Conservative government updated its advice on mobile phones to give school leaders in England the power to ban their use during the school day.
The new measures will be put in place across all of Ormiston's schools - which include six primaries and 32 secondaries, spanning as far north as Cheshire and as far south as the Isle of Wight.
Eight of its secondary schools have already adopted the policy for the autumn term after consultation with parents, while access to phones is also already prohibited at the trust's primary, special needs and alternative provision schools.
A spokesperson for the trust told the BBC the ban was following the "direction of travel" in England and it was about "taking the kids and parents with you".
In February, the Department for Education issued guidance to crack down on mobile phones to "minimise disruption and improve behaviour in classrooms".
One in five pupils had experienced bullying online, while one in three said phones are used in the majority of lessons without permission, she added.
A committee of MPs in May said the government should consider proposals to ban smartphones for under-16s, outlining "serious dangers" posed to children online.
Prime Minister Sir Keir Starmer has said he is not in favour of "simply banning" phones for under-16s but there is a "serious question" to be asked about what children can access.
Meanwhile, Technology Secretary Peter Kyle has told the BBC he is looking very closely at the impact of an upcoming Australian ban on social media for all under-16s.
The Australian government has promised to introduce legislation this year to enforce a minimum age for children to access social media.