Eton College has banned smartphones for students in their first two years at the school amid growing concerns over their impact on mental health and behaviour.
From September, the school which was attended by both Prince William and Harry, will issue boys with a Nokia handset that is not connected to the internet and can only be used to make calls and send texts.
The move comes after £23,000-a-year Alleyn's School in Dulwich urged parents not to buy their children smartphones, and All Saints Catholic College in Notting Hill introduced an 11-hour day partly to break pupils' addiction to the devices.
The head of the £21,000-a-year Streatham and Clapham High School has also urged parents to keep phones out of their children's bedrooms and to only buy phones for their children when “absolutely necessary.”
The new rules at Eton apply to pupils in the first year, who are aged 13 and in year nine.
Mike Grenier, Eton's deputy head overseeing pastoral care, wrote to the parents of new boarders saying that their child's smartphone should be taken home after its SIM card is transferred to a school-issued Nokia handset.
He said: “When used responsibly and in moderation, [smartphones] can be a key part of life for the modern teenager and can create positive social networks and give access to news and views from around the world.
“However, despite these positives, there are also associated challenges and potential areas for concern, especially around socialisation, misuse and overuse and the impact on both mental and physical health.”
The school said “age-appropriate controls remain in place for other year groups”.
There is a growing movement to stop children from using smartphones, and membership of the campaign group Smartphone Free Childhood is increasing. Joe Ryrie, the group's co-founder, told The Times: “We have to ensure it's not only the most privileged in society who are able to effectively protect their children.
The data shows that the harms caused by smartphones affect those in the lowest economic households the most.
On average, they spend twice as much time a day on screens, and are twice as likely to report being physically threatened online.”
Andrew O'Neill, head of All Saints Catholic College in Notting Hill, who extended the school day until 6.15pm, told The Standard: “Phone addiction is a real problem.
“The issue is that social media crept up on everybody … It's almost like our young people are brand managers, and there is no retreating from it or hiding from it. It's a constant.”