Schools are being told to improve standards after inspectors found more than a quarter in the county were failing.
Letters have been sent out by education chiefs at Northumberland County Council to all headteachers warning them that complacency will not be tolerated.
The move comes following a focused inspection by Ofsted in October which found that three-quarters of schools in the county had declined or not improved.
A total of 17 schools were part of the focused inspection with four placed in special measures, nine judged ‘satisfactory’ and one rated ‘outstanding’.
In a damning letter, Ofsted’s regional director for the north east, Nick Hudson, said support provided by the local authority in the schools placed in special measures had not been effective while actions to tackle weaknesses had not been swift enough.
As a result, Daljit Lally, corporate director of children’s services, sent out letters to headteachers last week outlining a raft of changes and how the council wanted to improve standards again.
Ms Lally said: “As a council we’re looking at a range of issues to help support schools following the recent Ofsted inspections.
“As part of this process lots of internal work is going on to ensure that we provide a positive response and we will be advising schools of the arrangements in due course.”
But the letter has been criticised by the National Union of Teachers (NUT), which believes headteachers are being ‘threatened’ by the council.
Mike McDonald, regional secretary for the NUT, said: “I thought it was a strange letter for the authority to send to schools and not particularly helpful.
“It’s far better if you’re seeking to bring about change that you take people with you rather than drag them kicking and screaming. This isn’t supportive. This is bullying, cajoling, threats and intimidation.
“We haven’t seen the detail of it and therefore it depends how they do it but I’m not aware the authority has that sort of power over individual schools.”