Education chiefs have warned governing bodies at more than a dozen under performing schools in Suffolk that they may be removed unless urgent improvements are made.

Suffolk County Council has sent letters to about 15 of its maintained schools, which it has declined to identify, where “serious concerns have been raised”.

Governing bodies at these schools have been told to provide “detailed recovery plans” to restore “effective leadership and management” within 15 working days of receiving the letters.

Failure to comply with the requirements could result in a range of “formal interventions” being carried out in accordance with the Education and Inspection Act, the letters warn.

Possible measures include the council replacing the governing body with an interim executive board, which would take over responsibilities including the management of the budget, curriculum, staffing and pay. It would also take over the appointment of the headteacher and deputy head.

Nikki Edwards, assistant director for education and learning at the council, said: “Historically we have not intervened quickly enough with our maintained schools or held them to account and therefore not ensured that all Suffolk children receive the best quality of education that they deserve.

“Given the council’s responsibility for our children’s education it is key that we robustly challenge schools that are consistently under-performing and not making the expected level of achievement.”

The Suffolk branch of the National Union of Teachers has accused the council of “bullying” schools with “heavy handed” letters and suggested it would be better to offer the governing bodies advice and support.

Graham White, NUT branch secretary, said: “If Suffolk wishes to raise standards in schools then avoiding these bullying tactics and actually spending more on education would be a start.

“Raising the Bar has some interesting ideas and is in some ways similar to the London Challenge which was so successful, however, Suffolk is trying to do that on a shoestring budget whereas London Challenge was properly financed.

“Suffolk appears to pick and idea as being the saviour of education, the truth however is that improving education takes time, money, resources and commitment by pupils, parents, teachers and the local authority.”

Ms Edwards, has defended the council, saying it had taken “targeted action to ensure that standards improve for pupils”.

“The outcomes for children are simply not good enough and we have a collective responsibility to acknowledge this and address it,” she added.