A petition calling for an independent watchdog to monitor the new relationships and sex education (RSE) curriculum has been signed by over 38,000 people.
The curriculum, which critics fear will sexualise children, becomes mandatory from this month, although schools were given permission to delay implementation because of the coronavirus pandemic.
Under the changes, relationships education is now compulsory for all primary and secondary school children. Sex education is mandatory for secondary school pupils, and health education is compulsory in all schools except independent schools.
While parents have some rights to withdraw their children from sex education, there is no right of withdrawal from relationships education.
Government guidance states: "Pupils should be taught the facts and the law about sex, sexuality, sexual health and gender identity in an age-appropriate and inclusive way.
"All pupils should feel that the content is relevant to them and their developing sexuality. Sexual orientation and gender identity should be explored at a timely point and in a clear, sensitive and respectful manner.
"When teaching about these topics, it must be recognised that young people may be discovering or understanding their sexual orientation or gender identity.
"There should be an equal opportunity to explore the features of stable and healthy same-sex relationships."
A petition started by The Values Foundation on CitizenGo warns that the curriculum will expose children to "misleading" ideas about gender ideology.
"Government-funded lobby groups are producing materials designed to be embedded in every section of the curriculum which promotes gender ideology and challenges children to think about whether or not they are really male or female by comparing themselves with gender stereotypes," it reads.
"Such teaching is purely ideological, misleading and confusing to children as well as being in complete opposition to the science curriculum."
It warns of sexually graphic content that is encouraging young people "to experiment with and explore niche adult practices".
The foundation has launched a new website, RSE Review, to keep parents informed about the curriculum.
The petition calls on the Government to create an independent board of advisers tasked with overseeing the safeguarding of children in the implementation of the RSE curriculum.
"The intention of RSE is to keep children safe yet it is currently exposing children to harm," the petition adds.
Another petition on the Parliament website asking that the parental right of withdrawal be protected was signed by 118,000 people.
The RSE curriculum has been widely criticised by Christians.
Charlie Colchester, founder of the Let Kids Be Kids Coalition, which is seeking a judicial review against the curriculum, told Christian Today that relationships education was "sex education by a different name".
"They are putting materials into the relationships education which used to be under the banner of sex education, where there is still a right of withdrawal," he said.
"With the relationships education, there is no right of withdrawal and that is both unacceptable and quite frankly, in our contention, illegal."
The Christian Institute has warned: "At a time when there is growing alarm at the sexualisation of children, this package of change could lead to the sex education industry, which promotes explicit materials, having much greater influence."
