Ofsted has warned that there is a growing north-south divide in education standards, particularly in secondary schools, with many in the north starting to fall behind. 

In its annual report on education standards, the watchdog said that approximately a third of schools it inspected in the north and the Midlands were adjudged to be not good enough. 

Ofsted chief Sir Michael Wilshaw says more attention must be focused on regions away from London, with too many schools in these areas now finding themselves "languishing in mediocrity". 

"This gap is a worrying one. We don't want to see a divided country after the age of 11," Sir Michael said of the report's findings that there are continued strong grades in the south and London, and weaker results in general in the north and the Midlands. 

Of the 16 local authorities nationwide where less than 60 per cent of pupils are attending good or outstanding schools and have below average "attainment and progress" in terms of their work towards GCSEs, 13 are in the north or the Midlands. 

Sir Michael went on to say that what needs to be seen in local authorities in these areas is for a higher standard of teacher recruitment, as it can often be a result of sub-standard teaching that sees them struggle. 

"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 said.

Brian Lightman, head of the ASCL head teachers' union, said part of the problem is that schools in challenging areas can come across significant difficulties when it comes to recruitment in certain subjects. 

Education Secretary Nicky Morgan said there should be a nationwide effort made to tackle these problems. "More needs to be done to deliver educational excellence everywhere," she said.

"That's why we are introducing new measures to transform failing and coasting schools, funding the best academy chains to share excellence in struggling regions in the north and creating a National Teaching Service - sending some of our best teachers to the areas that need them most."