Hundreds of parents have kept their children home from school, over the teaching of LGBT rights and homophobia.
Protests have taken place at Parkfield Community School in Alum Rock, Birmingham, amid parents' concerns about its No Outsiders programme.
Parent Fatima Shah said the scheme was "not age appropriate" and "not what we send children to school for".
The school has declined to comment but previously said it did not intend to change its teaching.
About 741 pupils aged from three to 11 attend the school that was rated "outstanding" by Ofsted in 2016 in the predominantly Muslim area.
Parents claimed 80 per cent of children had been kept home on Friday, however the school would not confirm the number of absent pupils and the BBC saw some children being dropped-off in the morning.
No Outsiders was created and piloted by the assistant head Andrew Moffat, with the aim to educate children to accept differences in society.
He previously said he had "received threats" over teaching the project.
Parent Maqsood Hussain said: "We have no discrimination against people of transgender or LGBT persuasion, we as a community are very welcoming of those people.
"But our children and the ages they are actually providing this material is inappropriate."
Fellow parent Fatima Shah said: "It is not age appropriate.
"We have no problem with the Equalities Act, we have no problem with them teaching them British values, but this is not teaching them British values, this is promoting homosexuality, this is confusing children.
"Children are coming home, girls are asking whether it is true they can be boys, boys as young as four asking whether it is true we can be girls. There is no need for it."
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