It's understood at least 60 students were either sent home or left sitting idly in a room for hours on Monday and Tuesday. Some students were warned about the crackdown verbally last week, while an official letter was only made available on Monday afternoon.

Jamie White said her 16-year-old son was taken out of class straight after roll call because his black shorts had a tiny white Nike logo on the side, while her 15-year-old daughter Stephanie was offered a light summer dress to wear by staff because her pants had elastic at the bottom.

She was only told of the uniform error in a phone call from staff on Monday.

"I've always taught my children to respect the uniform and respect the teachers ... but in saying that, I don't agree with what they're doing, and I don't agree with how they're tackling it," Ms White said.

"They've really come down on the uniform policy out of nowhere. I think there would have been a lot more happier parents if they gave more warning."

Ms White said she was told a letter had been issued in 2014 but does not remember receiving one, and noted the school had done nothing to enforce the policy this year until now.

A copy of the letter outlining the "blitz" was uploaded to the Kanahooka High School Facebook page on Monday evening, with an explosion of comments from enraged mums and dads. From nearly 100 posts, the main complaints included a lack of communication by the school, claims that the school had breached uniform policy codes as set out by the Department of Education, and concerns over the sudden expense of buying new clothing so late in the year.

The department codes state a school's uniform policy must be the result of formal consultation with students, teachers and parents; the policy should also take into account the diverse nature of the population and not disadvantage any student; while those who did not wear the appropriate uniform should not be prevented from continued participation in essential curriculum activities.

Kanahooka High principal Chris Toohey did not return the Mercury's call for comment on Tuesday but the school later issued a statement which denied that any students were sent home without parents' permission and said the dress codes originally came into force in 2011 with all students, parents and community members made fully aware.

It also said parents and carers were again notified more recently through newsletters.

Another parent, who wanted to remain anonymous, criticised Ms Toohey after both her daughters were punished for wearing pants that were cuffed at the bottom.

"I don't send my daughters to school to sit in a room.

"I can understand if it's a health and safety issue, but they've been wearing the same pants all winter," she said.