Hundreds of schoolgirls have been sent home because their skirts were too short as part of a crackdown to prepare pupils for the 'world of work'.
Teachers at Ryde Academy on the Isle of Wight either sent home 250 girls, aged between 11 and 18, or took them out of their classrooms to be placed in an isolated hall.
Others were sent home to change because their trousers were 'too tight'.
Boys at the academy were turned away if they arrived at lessons without leather shoes.
Dr Rory Fox, the headteacher at Ryde Academy, said skirts must be 'worn to the knee' and that trousers cannot be 'close fitting'.
He said the issue of school uniform was becoming 'increasingly problematic' in his letter to parents. Year 7 and Year 8 students with 'incorrect' uniform were kept on site but removed from lessons.
Meanwhile, older pupils in Year 9 and Year 10 were ordered to return home to change.
But the initiative was met with fury by parents.
Helen Smith, whose 14-year-old daughter Jade was sent home twice on the same day, said: "The school had an inset day on Monday and we spent the whole day trying to find a new skirt.
"I finally bought one for £8 and thought it would be perfect - it was knee length. But when she went to school she was immediately sent home because they said her skirt was too short.
"It was the perfect size, it was not 'too short' - I would not have bought it otherwise."
She said she rushed down to the school to pick her up, then bought some trousers which cost £15.
But when her daughter went back to school she was told the trousers were 'too tight' and Jade was sent home again.
Helen said: "It has been a nightmare. I just can't understand why the school have decided to do it five weeks before the end of the year."
But Dr Fox defended the measures, saying: "At Ryde Academy we have high expectations of our students. As the weather has improved over the last couple of months, a number of uniform issues have become apparent amongst students.
"The Academy wrote to parents on 27 May about what was appropriate and there has been extensive discussion with students, as well as a number of assemblies since then.
"The Academy sent a second letter to parents on 9 June to inform them that there would be a uniform focus on the 17 June.
"Parents were informed that if students' uniform was still not correct on that date, then older students would be sent home to change and younger students would be educated apart until their uniform issues could be addressed.
"We are grateful to the very many parents who support us on a day to day basis by ensuring that their children arrive at the Academy in the agreed uniform, and help to uphold the standards of dress/uniform that Ryde Academy expects.
"The governors and staff are conscious that we are preparing students for the world of work and so it is important that our students understand the importance of managing their appearance and working within the framework of a dress code."
More on Parentdish: Schoolgirl suspended for 'too short' shorts