Schools should be aware of the potential impact of the "shadow" education system of private tutoring, an academic has warned.
Studies have shown that private tutoring can exacerbate social inequalities, but that state-funded, one-to-one tuition, such as that provided under the Every Child a Reader and Every Child Counts programmes, can reduce the gap between rich and poor.
Judy Ireson of London University's Institute of Education said that at present the size of the "shadow system" may not be a major concern in England, but in other countries where it becomes extensive it can have a negative effect on mainstream education.
Teachers, she said, may put less effort into their classroom teaching when they realise that students will cover the work with their tutors.
"If we had the kind of system where teachers know children are going off to get tutoring it might affect their teaching," Professor Ireson said.
"They could adapt their maths, for example, so that the school focuses on areas that the private tutor doesn't. But, again, children who don't go to the private tutor would then potentially lose out."
The Government is currently introducing changes to the state system that will mean less national control. Schools will be encouraged to use their budgets to find interventions that suit their pupils.
Professor Ireson said: "I don't think that Every Child Counts would have happened unless the (previous Labour) government had invested in it, so I do think that sort of work is important because individual schools would not have the resources to develop a programme like that on their own.
"Programmes like Every Child Counts and Reading Recovery (part of Every Child a Reader) seem to have been successful in helping less advantaged children make progress, whereas private tutoring is out of the reach of people who don't have the money to pay for it."