More than 100 unqualified teachers were working at state schools in Nottinghamshire last year, figures reveal.
Teachers' union NASUWT said that every child has the right to be taught by a qualified teacher, and called for the Government to force schools to hire fully trained staff.
Department for Education data shows there were the equivalent of 5,213 full-time classroom teachers in the area’s state-funded schools in 2018.
But 137 of those neither had qualified teacher status nor were working towards it.
Teachers require QTS to work in schools overseen by councils.
It means about one in 33 teachers in Nottinghamshire state schools do not have QTS, which is gained after getting a recognised teaching qualification and completing practical training.
Academies, which are state-funded but are not run by local authorities, can employ teachers without QTS.
Across England, there were the equivalent of around 383,400 full-time classroom teachers working in state schools in 2018.
Of those, about one in 25 did not have QTS and were not on the way to gaining it – around 14,800 in total.
Chris Keates, general secretary of the teachers’ union NASUWT, said: “A child has the right to be taught by a qualified teacher. What we should be working towards is a qualified teacher for every child.
“Internationally, high-quality education is associated with employing high-quality staff in schools.
“We have been very clear that what the Government should do is return to a position where, certainly in state-funded schools, there is a requirement to employ a qualified teacher.”
Councillor Philip Owen, chairman of children and young people’s committee at Nottinghamshire County Council said:“Employing any staff is the responsibility of the headteacher and the governing body of school where people are employed. The head and governing body need to ensure that the standard of teaching is at the appropriate level to meet the needs of their pupils.
“Simply because someone does not have a formal teaching qualification it does not mean that they cannot deliver the curriculum
“Having a formal teaching qualification does not automatically mean that a person is a good teacher.
“Employing a person to teach without a formal teaching qualification is dictated by the circumstances in which they’re employed.
"They are often employed to teach in a subject area where there has been a shortage of teachers for a considerable period of time, such as maths or physics for example.
"Therefore it is far better to have someone with an academic qualification in those subjects, than to have no-one at all.
"Any head teacher and governor will want to ensure that they are working to ensure their pupils attain the best possible educational outcome.”
Kevin Courtney, joint general secretary of the National Education Union, said the use of non-QTS teachers demonstrates the teacher recruitment and school funding crisis.
He added: "It is vital that the Government addresses the root causes of teacher recruitment and retention, and starts to give schools the funding they need to ensure every child has the education they deserve."
A Department for Education spokesperson said: “More than 95% of teachers in state-funded schools have qualified teacher status and last year saw an additional 34,500 new trainee teachers recruited, despite an extremely competitive labour market and the lowest levels of unemployment for decades, showing that teaching continues to be an attractive profession.
“We want children to have great teachers who can inspire and excite them so have given schools the freedom to employ experts, such as scientists, sports people or musicians, to add value and improve the learning experience for pupils.”