Dozens of academies have been issued warning notices by ministers or face government intervention due to below standard results, it has emerged. 

The Department for Education has written to more than 30 academies around concerns about their overall performance, spelling out in some cases that the performance of their pupils is “unacceptably low”.

Since 2011/12 it has come to light that 15 of the government’s flagship academies had been issued with “pre-warning” letters, but today the DfE has released an additional 19 letters spelling out that academies should improve or risk being taken over.  

The news comes in the same week after the Commons Education Select Committee revealed it is launching an inquiry into the academies and free school programme, over concerns around governance and general performance of the schools.

Among those academy sponsors with the highest number of schools in need of improvement is the Academies Enterprise Trust, which has seven academies on the list of 34 in need of boosting their performance.

Out of all the academies to be issued with warning notices, six have seen their academy sponsors changed including the Unity Academy in Middlesbrough and Thetford Academy in West Suffolk. 

A spokesperson for the DfE said the majority of sponsored academies were “thriving under great leadership” but added that in “a minority” of the state independent schools, results remained “stubbornly low”. 

“We will not tolerate long-term under-performance in any school - including in an academy,” the DfE said. “That is why this government issues pre-warning letters and warning notices. The evidence shows that academies respond well to these warnings, achieving on average much better GCSE results afterwards. 

“However, as with maintained schools, if these academies still do not make the progress we expect, we will take further action. This may result in a change to the sponsorship arrangements.”

On Wednesday this week, the Commons Education Select Committee said it would look into how well the government is performing in spotting and supporting struggling academies. 

But the Association of Teachers and Lecturers (ATL) said so many academies being issued notices merely served to show the secretary of state had too much power. 

“If you think becoming an academy will provide you with the freedom and autonomy you want then it is worth reconsidering given that the secretary of state has the power to strip and appoint a sponsor,” ATL general secretary Mary Bousted said. 

“What this shows is that you always have to serve someone as a school, be it a local authority or a secretary of state and given who is secretary of state at the moment I know which one I would choose.”