Four students were asked to leave Smestow School in Wolverhampton yesterday after choosing to wear the blue uniforms to classes.
Today the families of the schoolchildren involved condemned the decision, saying it was disrespectful.
But headteacher Martyn Morgan said it was school policy for children to wear their uniforms at all times.
Should the poppy day cadets have been sent home? Vote in our poll below and have your say in the comments below:
Among those sent home were Year 11 pupils Elle Phillips, aged 15, Aman Nanglu, also 15, and Rezanne Willis, 16, who are all members of the 1047 City of Wolverhampton Air Training Corps squadron.
They decided to wear their uniforms to pay tribute to fallen soldiers as the nation fell silent during the two minute act of remembrance. But they were told they could not return to the school on Windmill Crescent until they had changed back into their jumpers and ties.
Elle's father, project engineer Paul Phillips, aged 47, of Woodland Road, Merry Hill, was contacted at 11.30am by the school to inform him his daughter would be leaving at midday to change.
"I don't think there is anything wrong with it. In fact, I am proud that Elle wanted to wear it. She is a very good student and she feels strongly about it." Elle added: "We thought it was just respectful to show it wouldn't just be a normal day. We wanted to show it does actually matter."
Oldbury poppy collection box theft pair jailed for 12 months
Sales assistant Meena Kumari was at work when she heard her son Aman had been sent home. She said: "I'm utterly shocked. These youngsters take a lot of pride and they are on the right track. Why can't the school see why they are doing it?"
Headteacher Mr Morgan said in a statement that the decision was made according to policy.
He said: "Four students were sent home from school today as they were not wearing school uniform. They were asked to return to school once they had changed into school uniform. As is our normal practice the parents of the students were contacted first and we made it explicit that they should return to school once changed.
"This process is in line with the guidelines in the Department for Education publication 'School Uniform A Guide for Headteachers, Governing Bodies, Academy Trusts, Free Schools and Local Authorities'."
Should the poppy day cadets have been sent home? Have your say in the comments below: