More than one in four secondary pupils have had private tutoring, according to polling by social mobility charity the Sutton Trust.
The polling of 2,809 pupils, published today, found that 27 per cent of 11- to 16-year-olds had received private tuition in the past two years, compared with 18 per cent when the survey began in 2005.
Pupils from more affluent homes were more likely to have had a tutor, with 34 per cent of those from "high affluence" backgrounds saying they had private tuition, compared with 20 per cent of those from "low affluence" homes.
But the proportion of pupils with a private tutor had dipped slightly from levels in 2017, when 30 per cent said they had had tuition.
The study also found that tutoring was especially prevalent in the capital, with 41 per cent of London’s teenagers reporting they had had a private tutor.
In addition, nearly a quarter of secondary school teachers – 24 per cent – had taken on private tutoring over the last two years.
According to the report, teachers were most likely to have taken on tutoring after direct contact from parents.
The charity has called for the government to introduce means-tested vouchers for lower-income families to access more private tuition.
And its sister organisation, the Education Endowment Fund (EEF), has suggested that state schools should use their pupil premium funding to prioritise one-to-one and small-group tuition, as it said this is a cost-effective way to boost pupils' achievement.
The charity also called for more tuition agencies to deliver some of their services to disadvantaged pupils.
Sir Peter Lampl, Sutton Trust founder and chairman, said: "Private tuition is widespread, 27 per cent of teenagers have been tutored rising to 41 per cent in London. A quarter of teachers have provided tutoring.
"With costs of at least £25 per session, many parents can't afford it.
"The government should look at introducing a means-tested voucher scheme to enable lower-income families to provide tuition for their children.
"Schools should also consider the implications of teachers offering paid tuition outside of lessons and how this is promoted in school."