However, there has been greater improvement in the South of England, where 79 per cent of schools are now good or outstanding, compared to the North and Midlands, where just 68 per cent of secondary schools met the standard.

Chief inspector Sir Michael Wilshaw said some schools had “failed miserably year after year after year” adding that the problem could not be down to deprivation, since primary schools fared much better.

“This gap is a worrying one. We don’t want to see a divided country after the age of 11. We’ve seen a significant difference in the quality of teaching between the South and the midlands and the North, a significant difference in terms of the quality of leadership… and we need to worry about this as a nation,” he added.

“The mediocrity in secondary performance should be a national concern – and the mediocrity is residing mainly, but not exclusively, in the midlands and north of England.

“If the ‘northern powerhouse’ is going to mean something, then we’ve got to improve educational performance in our secondary schools north of the Wash.”

Compared to secondary school children in the South, those in the North and Midlands on average made less progress in English and maths, perform worse at GCSE and attain fewer top grades at A-level, he highlighted.

“If left unaddressed the consequences will be profound. Our society, our future prosperity and development rely on the better education of our children. As things stand, too many secondary schools in the North and Midlands are failing to equip young people with the skills and knowledge they and the country need.”