If performance still failed to improve, academic selection should be brought back, he told its annual conference.
The government said there had been "major improvements" in recent years.
In 2006, 43.8% of youngsters obtained the Department for Education and Skills attainment benchmark of the equivalent of five good GCSEs including English and maths.
Mr Frost said: "It is nothing short of a national disgrace. This is in the 21st century, not Victorian Britain."






