Chris Parry, the new chief executive of the Independent Schools Council, warned state schools are struggling with unteachable children, ignorant parents, staff who did not want to be there and headteachers who did not understand leadership.

His comments were branded "insulting" and "deeply misguided" by the Government.

He said comprehensive school pupils could not be expected to get into top universities if they were bullied by classmates from "disadvantaged backgrounds".

Speaking of the state sector, he said: "There are too many leaders but not enough leadership, there are a lot of managers but not enough management. There aren't enough teachers and aren't enough teachers in the subjects we need. It's lacking human, material (and) financial resources."

He said children might flourish if they are taken out of their state school and put in a private school, but they would fail again "if they go back to anarchy and chaos" of a troubled home.

Mr Parry added there are a lot of "wonderful" teachers, but it was a question of making sure there were good teachers in every school.

Earlier this month he attacked the "Cold War" mentality of some figures in education for perpetuating the "severe sectarian divide" between state and private schools and condemned the "very poor" quality of state education for forcing thousands of parents to pay to go private.

A Department for Children, Schools and Families spokesman said: "This is a deeply misguided picture, and frankly insulting to the hard-working and talented teachers and pupils in the state sector.

"School standards have never been higher, Ofsted tells us that the state sector has the best generation of teachers ever, and that in over 95% of schools behaviour is satisfactory or better."