The heads of two Canterbury schools have hit back at the “improve or close” warning from the Government.

Canterbury High and Chaucer Technology are among 638 in the country that did not achieve government targets that require 30 per cent of students to get five A* to C grades at GCSE, including English and maths.

The Community College, Whitstable, is another.

Schools secretary Ed Balls is recommending that failing schools become academies and is demanding they meet the target in the next three years.

If they do not meet the targets they will be closed and replaced with a new “trust” school.

At Canterbury High 27 per cent of students achieved the target and only 24 per cent at Chaucer and 23 per cent at the Community College.

Canterbury High head teacher Phil Karnavas says it is unfair to judge the school in an area where the strongest students in subjects such as English and maths go to grammar schools.

He said: “It is hugely unfair to judge schools in a fully selective authority against a criteria that places them at an inevitable disadvantage.

“While maths and English have importance as subjects, they are not the only important subjects, nor are they the only important thing.

“It’s important students leave school feeling confident and positive about their future. You don’t do that by telling them they are failing or that they are at a school that’s failing.”

He believes value-added tables, which chart the academic progress of a child, are a much better way of judging a school.

Head teacher of Chaucer Simon Murphy agrees. He said: “I think value added tells much more of an important story.

“This measure is a crude tool and if parents thought this was a measure of a school, they’d be missing a trick.

“But I can understand the drive to push English and maths. I arrived just under two years ago and it’s a priority of this school to raise its game.”

See the full list of schools under threat