Hundreds of thousands of children - some as young as two - now receive private tuition at a cost of between £7 and £60 an hour.
Parents say the extra study gives their children confidence and higher grades, but headteachers say the tutoring market is “trading on insecurity”.
Interviews with seven tutoring agencies reveal that: One already large tuition business has seen 42% growth over the past year.
One agency is recruiting 100 new tutors a month to cope with demand. One has opened more than 50 extra study centres over the last year.
Parents, such as Batool, from north-west London, who does not want to give her full name, said many in her social circle now paid for tuition.
“Private tutoring has become normal,” she said. “Parents are more aware of the failings of the state education system and the importance of which university your son or daughter goes to than they used to be.”
Batool, a single parent on £29,000 a year, spent £1,400 over Easter on an A-level revision course for her daughter, Wafa, and pays £36 a week for two hours of chemistry and physics tuition.
The agencies claim the growth comes from parents on low incomes and ethnic minority families who are making substantial sacrifices to help their children.
Fleet Tutors, a national home tuition agency, has seen student numbers rise by 42% to more than 10,000. London-based agencies Tutor House and Holland Park Tuition reported increases of 30% and 27% respectively.
Kumon, which takes children as young as two, has 658 centres. In 2006 it had just over 49,000 children, mainly of primary school age - now it has almost 70,000.
Explore Learning, which has 78 centres, was bought by its management last August, with the backing of a private equity firm, for about £30mn. In 2008 it had enrolled 4,600 children; now it has more than 20,600.
Kip McGrath, one of the biggest tuition businesses, has expanded from 187 centres to 210 over 12 months. The average cost per hour of private tuition is about £40, according to the Good Schools Guide.
Some, such as Holland Park Tuition, charge £58 an hour.
Kip McGrath and Explore Learning are well below this at £27 per 80-minute session and £7-£15 an hour respectively.
Along with Kumon, though, they do not provide one-to-one tuition.
Mylene Curtis, managing director of Fleet Tutors, said: “We’ve seen greater diversity in the socio-economic profiles of parents we serve and more non-British families. Tutoring is no longer regarded as something only affluent middle-class parents consider to get their children into their school of choice.”
Explore Learning claims 14% of the children it tutors are in the ‘most deprived homes’ in the country.
Jan Long, director of the Southampton centre of Kip McGrath, said it was not unusual for grandparents to contribute to the cost. “I hear a lot of concern about individual children being left behind and that state schools are not challenging brighter students,” Long said.
“Parents are worried about our education system and don’t want their child to get lost in it.”
Janette Wallis, senior editor of the Good Schools Guide, said the number of parents asking for tutor recommendations had risen by almost 50% in a year.