Council bosses said the protest resulted in around 30 primary pupils missing school and had "taken action" against parents who pulled took their children out of George Tomlinson School in Leytonstone, east London, but refused to state what sanctions are being taken.
Pervez Latif, a 41-year-old accountant whose children Saleh, 10, and Abdurrahin, nine, attend the school, said his wife Shaheen, 38, was worried they could be taken to court.
He said: "My wife is very concerned she might be prosecuted.
"As yet we haven't heard anything from the council about whether they are taking action."
He said he knew of about 30 children who had been taken out of classes during the Lesbian, Gay, Bisexual and Transgender Week after parents objected to their youngsters being encouraged to "celebrates the lives and achievements of lesbian, gay, bisexual and trans people in the community".
Under current laws parents can be prosecuted for failing to ensure their children attend school.
Mr Latif, from Leytonstone, said: "We were worried because weren't sure how they were going to teach our children these issues.
"We don't think it is necessary to teach it for a whole week and the children are so young. It is more appropriate for secondary school.
"Most children that age don't understand these things. When we took our children out of school we had to explain why - they didn't know what two parents the same sex meant."
A spokesman for Waltham Forest Council refused to reveal how many children missed lessons or what action would be taken against pupils but the council's website said parents of truant youngsters can be asked to sign a contract, given an on the spot fine or hauled into court.
The spokesman added: "As part of the borough's policy of promoting tolerance in our schools, children are taught that everyone in our society is of equal value.
"At George Tomlinson, parents were invited to meet with teachers and governors several weeks ago to discuss what work would be taking place throughout the national LGBT History Month, and how this work would be delivered.
"Regrettably, some parents chose to remove their children from school.
"The council does not condone any unauthorised absence from school and action has been taken."
Pervez Latif, a 41-year-old accountant whose children Saleh, 10, and Abdurrahin, nine, attend the school, said his wife Shaheen, 38, was worried they could be taken to court.
He said: "My wife is very concerned she might be prosecuted.
"As yet we haven't heard anything from the council about whether they are taking action."
He said he knew of about 30 children who had been taken out of classes during the Lesbian, Gay, Bisexual and Transgender Week after parents objected to their youngsters being encouraged to "celebrates the lives and achievements of lesbian, gay, bisexual and trans people in the community".
Under current laws parents can be prosecuted for failing to ensure their children attend school.
Mr Latif, from Leytonstone, said: "We were worried because weren't sure how they were going to teach our children these issues.
"We don't think it is necessary to teach it for a whole week and the children are so young. It is more appropriate for secondary school.
"Most children that age don't understand these things. When we took our children out of school we had to explain why - they didn't know what two parents the same sex meant."
A spokesman for Waltham Forest Council refused to reveal how many children missed lessons or what action would be taken against pupils but the council's website said parents of truant youngsters can be asked to sign a contract, given an on the spot fine or hauled into court.
The spokesman added: "As part of the borough's policy of promoting tolerance in our schools, children are taught that everyone in our society is of equal value.
"At George Tomlinson, parents were invited to meet with teachers and governors several weeks ago to discuss what work would be taking place throughout the national LGBT History Month, and how this work would be delivered.
"Regrettably, some parents chose to remove their children from school.
"The council does not condone any unauthorised absence from school and action has been taken."
