Hundreds more schools risk being taken out of council control under new government measures to identify ‘coasting’ sites.

A new Education and Adoption Bill will see secondary schools considered for intervention if fewer than 60% of pupils achieve five A* to C GCSEs - including English and maths – over 2014 and 2015, targets are missed in 2016 and progress is consistently low over three years.

Primary schools will be labelled ‘coasting’ if fewer than 85% of children achieve an acceptable standard in reading, writing and maths.

Education secretary Nicky Morgan expects hundreds of schools could be landed with the ‘coasting’ title, potentially being forced to convert into academies – out of local authority control – if they fail to create a credible improvement plan.

Morgan said: ‘For too long a group of “coasting” schools, many in leafy areas with more advantages than schools in disadvantaged communities, have fallen beneath the radar.

‘I’m unapologetic about shining a spotlight on complacency and I want the message to go out loud and clear, that education isn’t simply about pushing children over an artificial borderline, but instead about stretching every pupil to unlock their potential and give them the opportunity to get on in life.

‘I know that schools and teachers will rise to the challenge, and the extra support we’ll offer to coasting schools will help them do just that.’

Deputy general secretary of the National Union of Teachers (NUT), Kevin Courtney, said: ‘Very many good secondary and primary schools – as defined by Ofsted, and as defined by parents – will now be classified as coasting. They will now stand the risk of losing their heads and other staff as uncertainty reigns in their school.

‘Nicky Morgan says that coasting schools will ultimately be transformed into academies, but by her own definition very many academy schools will also be coasting.

‘The NUT has consistently argued that it is the job of local authorities to assist schools. The London Challenge, unwisely scrapped by the Coalition Government, was a proven success. Nicky Morgan would be wise to follow its example, instead of turning to regional school commissioners.’