The UK's education system is fostering a "cult of the average", failing to help the brightest youngsters, or those most in need, business leaders have warned.
In a damning indictment, the CBI said that too many children fall behind and never catch up, and that in some cases, secondary schools have become little more than exam factories.
Decades of "patchwork" reforms have confused schools, encouraged a tick box culture that has put off teachers and resulted in a narrow focus on exams and league tables, the UK's biggest business group said. In a new report, the CBI calls for a major overhaul to ensure that all children can succeed.
It recommends radical changes, such as reducing the importance of GCSEs and making A-levels the main exam for school leavers, and moving away from league tables in favour of Ofsted reports.
CBI director-general John Cridland said while businesses want school leavers to have a rigorous education, they also want it to be "rounded and grounded".
"Today we have a system where, sadly, a large minority of our young people fall behind," he said. "They fall behind and never catch up. It's not the fault of any individual concerned. It's not the fault of children, parents or teachers. It's a system failure. It's not acceptable any more than it's not acceptable that the top 10% are not stretched enough."
The report, published as the CBI meets for its annual conference in central London, says that the UK's schools have faced "35 years of piecemeal reforms".
Often, rather than being used as a measure of a child's achievement, exams have become "a tool for assessing school performance", Mr Cridland said.
Ministers have announced plans to scrap GCSEs and replace them with new English Baccalaureate Certificates in English, maths and science. Reviews of A-levels and the national curriculum are also under way.
A Department for Education spokesperson said: "The CBI rightly recognises the importance of English and maths, calls for greater rigour in the curriculum and in exams, welcomes the academy programme, wants a new accountability system and backs greater freedom for teachers. These are all part of the Government's radical package of reforms that will give England's education system the thorough overhaul it needs."