A headteacher branded the education secretary, Ruth Kelly, a "disaster" and said standards had "collapsed", it was reported today.
David Hempsall, head of the independent Queen Elizabeth grammar school in Lancashire, Blackburn, said in a speech at a prize giving ceremony that the national curriculum was harming children's development, according to the Times newspaper.
He is reported to have told parents and pupils: "Frankly, I don't care how many politicians say something to the contrary. Rigour has gone out of the window.
"Results are massaged so that they appear better than they are.
"Ministers - and the present one is a disaster - imply that standards over time have been maintained, which is absolute nonsense.
"The national curriculum is a disaster. Whilst it has some slight effect in raising the floor, it is academically and intellectually impoverished, however much teachers flex it."
He said some teachers had concentrated too much on preparing pupils for curriculum tests and the damage caused was "incalculable" in formative years and "virtually irreparable" by the time they went to secondary school.
"The waste of their potential makes me very, very angry," he is said to have added.
A Department for Education and Skills spokeswoman said standards in schools had "never been higher".
"The government has consistently prioritised education in its public spending commitments, and international studies confirm the strong performance and progress in our education system," she added.
