Pupils who protested against their school’s new “gender neutral” uniform policy have been locked out of the premises and sent home on the first day of term.
Dozens of pupils and parents gathered outside Priory School in Lewes, East Sussex to dispute a ban on girls wearing skirts.
The school said the new rules were designed to be practical and promote equality among students.
But the decision to bar demonstrators has been met with criticism.
Local MP Maria Caulfield said she was “very disturbed” that the school turned girls away for wearing skirts, while Tim Loughton MP, who attended Priory School as a child, said it was "political correctness gone mad again".
Cressida Murray helped organise the protest with her daughter Libby. She argued that some families cannot afford to buy the updated uniform, particularly as some will need it for less than a year.
Other students questioned the policy’s impact on the environment.
They brandished placards saying “A new uniform for nine months is not sustainable”, and “Fast fashion is the second biggest contributor to climate change”.
After the school sent home the protesters, many parents received messages asking them to explain their child’s “unauthorised absence”.
A spokesman for Priory School said: "We believe that a uniform worn without modification is the best way to ensure equality.
"We do not want children feeling vulnerable and stressed by the pressure they feel to wear or own the latest trend or status symbol."
Priory School also maintained that it is not alone in having trousers as uniform for all students, claiming that at least 40 other schools have a similar requirement.