A mother claims her daughters were excluded from school when teachers used rulers to see if their trousers were wide enough.
Barnsley Academy introduced a rule stating trousers must be at least 10cm wide on January 5, the first day back after Christmas.
But parents say they received no notice and were outraged when their children were sent home for wearing their normal uniforms.
Now Jane Ogden, aged 36, the mother of Ellie, 14 and Mollie Young, 12, who both attend the school, claims teachers have even gone to the extreme lengths of measuring pupils’ trousers with rulers.
She said: “The teachers are measuring trousers with rulers. They are lining the children up when they go in to school in the morning and do it in groups of tens.”
Mrs Ogden spent £72 on school trousers for her seven children at the start of the academic year.
But her daughter Ellie was excluded between Monday and Wednesday last week for her trousers being too tight, even though they were 13cm wide.
Nineteen other girls were excluded on the same day.
Mrs Ogden, said: “The school said that it was an ongoing problem and that they needed to show the children how to be respectful.
“I pride myself in my children giving me respect but I think we should respect them as well.”
She said the school had had a crackdown on other areas of the uniform as well and had banned makeup, piercings and nail varnish.
To stop her daughter being excluded or put in isolation again, Mrs Ogden has since bought a new pair of trousers for Ellie, which are 14.5cm in width.
The school has deemed the trousers suitable.
Mrs Ogden said: “Ellie is in year 10, so it’s a vital GCSE year and now she has to catch up with work.”
She added: “The school tells the girls that they can’t wear make-up but the teachers are plastered in it.
“They tell the students that they can’t wear short skirts but the teachers wear skirts that come just under their bums.
“It’s just one rule for one and another for another.
“You should be able to walk around naked and no one should bat an eyelid. What’s more important, school trousers or an education?”
A notice about the uniform changes posted on the school’s website, reads: “There is an increasing number of students wearing tight fitting trousers.
“Tight fitting trousers are unacceptable and are not allowed in the academy.”
The school is even using funding to pay for new trousers for some pupils, saying it ‘did not want to cause financial difficulties for parents’.
A spokesperson for the school, said: “The academy has a strict uniform policy which parents and students are fully aware of and which is being properly enforced.
“All students are expected to adhere to the policy.
“The academy is rapidly making good progress across the board and part of this is a renewed focus on attendance, uniform, standards and behaviour, which is proving popular with the majority of parents and students and leading to stronger educational outcomes.”