Growing numbers of parents who become embroiled in feuds with their children's teachers have been blamed for rising levels of persistent pupil absences.
New figures have shown an increase in Norfolk's 'ghost children', the term for those who miss more than half their lessons.
There are now 2,500 youngsters in this category, more than one in 50 pupils and a proportion experts have described as "a genuine worry".
They warn that the figure is increasing because of the growing numbers of parents who fall out with their children's school and remove them from lessons, sometimes over issues as trivial as uniform policies.
Scott Lyons, district secretary of the National Education Union in Norfolk, said there had been an increase in the parents passing on "anti-school attitudes" to their children.
"I think there has been a wholesale change in parents' attitudes in recent years and some have grown to have really anti-school feelings," he said.
Mr Lyons said that, particularly since the Covid lockdowns, parents had been far more forthcoming with complaints about how schools are being run.
He added: "I think a lot of that did come from Covid, where there was lots of people who were against mask-wearing and schools having to open and close all the time.
"Ever since, teachers have had parents coming at them from all angles.
"It doesn't take much for children to pick up on these negative feelings so it's no surprise to see the numbers of severe absentees going up.
"I think we now have a generation of children coming from 'anti-school' families and that is a big concern."
In recent months, some Norfolk schools have seen parents refuse to send their children in following rows over uniform policies.
Other boycotts have been prompted by disputes over the way that schools have handled allegations of bullying.
The new figures show that the number of ghost children has grown steadily in recent years, particularly since full classroom teaching returned following the pandemic.
Since 2018/19, the number has almost trebled, from 888 to 2,427 - with the percentage swelling from 0.9pc to 2.3pc.
The overall rate of absence, however, has taken a slight fall, from 8.4pc to 7.8pc.
Mike Smith-Clare, Labour's spokesman for education in Norfolk, said: "It is great to see that overall absence is lower this year - although the fact that severe absences are still high is a genuine worry.
"So many of these young people are heading towards becoming lost off the academic radar.
"Education is essential for all children and their futures - priority must be given to identifying the cause of these absences and rectifying them.
"If this does not become a key focus of our county's academies then our children's futures are being placed in serious jeopardy."
The statistics have also sparked calls from national charity Action for Children for families to be offered a greater level of wellbeing support.
The charity claims that severe absence often happens when a child is too anxious to go to school.
Joe Lane, its head of policy and research, said: "High levels of absence from school in England is a huge problem for the children missing school and their families.
"As well as providing an education, schools can support children to develop emotionally and socially, promote their wellbeing and help keep them safe."
Dame Rachel de Souza, children's commissioner and former Inspiration Trust chief executive, said it was important to ensure families "get the right help early".
She said: "Every child deserves to access their right to education."
A spokesman for Norfolk County Council said: "We are committed to working with schools and other partners to improve school attendance and punctuality across the county.
"The trends in Norfolk are similar to those seen nationally, much of which can be attributed to the long-term impact of the pandemic."
