Does private tutoring disadvantage low-income students?

Last year almost a quarter of 11 to 16 year olds (23%) in England had some form of private tuition. Of these over half (53%) were being coached for a specific test or exam.

With the number of parents paying for private tuition on the rise, are wealthy families gaining an unfair advantage? Particularly when it comes to preparing their children for entrance exams to grammar schools?