More than 80 pupils at a Maidstone academy have spent their first day back at school today sitting in the sports hall excluded from normal lessons, while others have been sent home for "unacceptable" behaviour.

The pupils at New Line Learning Academy failed to heed warnings from the school’s new principal Jane Hadlow that she would be coming down hard on those failing to meet the uniform rules.

Mrs Hadlow, who joined the school in October as interim head, taking over from David Elliot, issued several warnings of her intentions, but parents said they were ill-timed.

Mother Deborah King said: “My daughter Hayley was told just before Christmas that her trousers didn’t meet the code, even though she’s worn the same style ever since Year 7 and she’s now in Year 10.

“I had only just bought her a new pair of trousers in September, with Christmas and everything, I couldn’t buy her another pair.”

Mrs King is incensed because Hayley, who is now in her vital GCSE years, is missing classes.

"Is a pair of trousers really worth damaging her education?" - Deborah King

She said: “She’s spent all morning in the freezing cold sports hall with a just a book to look at. Is a pair of trousers really worth damaging her education?”

Hayley has been wearing skinny-fit trousers, but the regulation requires a skirt or straight trousers.

But the school said it had sent a total of four letters home, reminding parents of the need to comply, and had even held a uniform pop-shop at the school, so that parents could easily purchase the right gear.

Mrs Hadlow said: "We expect our students to wear the full and correct uniform with pride.

"Our uniform policy has not changed, but to reinforce our high standards. we gave our parents three months' notice to ensure all students attend school in the correct uniform from January 2017.

"I'm extremely grateful for the vast amount of support we have received from parents and carers, as well as students, in support of our high standards for not only for our uniform but across the academy.”

But father Patrick Mullervy, whose 13-year-old daughter Charlotte was sent home in tears, after wearing a non-pleated skirt, said: "I received no letters, or emails or phone calls.

"It's a complete farce. I bought Charlotte's skirt at the start of last term today from the school supplier.

"I've tried to order a pleated one today, and they are out of stock!"

The nearby Cornwallis Academy, another in the Future Schools Trust stable of schools, had a similar crackdown in November 2015, which resulted in a number of pupils being excluded for several days, and an irate grandmother being banned from the site.