Over 20,000 people have signed a petition calling for a watchdog to be established ahead of the roll-out of the Government's controversial new Relationships and Sex Education curriculum.
From September, Relationships Education will be compulsory for primary school pupils, and Relationships and Sex Education (RSE) for secondary pupils.
In Relationships Education lessons, young children will learn about "different types" of relationships, same-sex marriage and transgenderism.
RSE is to include teaching on "sex, sexual health and sexuality".
Books in the new curriculum are reported to include Are You A Boy or Are You a Girl?.
The Values Foundation, which started the petition on CitizenGo, said that many parents had "unquestioningly accepted" the claim that there was a "need" for compulsory RSE "without actually being aware of the content that their children may be being exposed to".
"At a secondary level, the RSE curriculum is introducing children as young as 13 to p0rnography and explicit graphic sexual content where they are encouraged to experiment with and explore niche adult practices," the petition reads.
READ MORE: What's so bad about sex education?
A recent survey by gay rights campaign group, the LGB Alliance, found that only a quarter of parents of children aged five to 16 were quite or very aware of the new curriculum.
The poll of 3,856 parents also found that over two thirds (69%) were supportive of Harry Potter author JK Rowling after she raised concerns about transgender activism and the risk to single-sex spaces.
The Values Foundation said it was important that schools are transparent about what they are teaching children, and that parents are properly consulted.
"The intention of RSE is to keep children safe, yet it is currently exposing children to harm," the petition reads.
"We are therefore calling on the government to introduce a series of measures which are designed to safely reflect the original intention of RSE and introduce a permanent, robust safeguarding procedure to be monitored by an independent board of advisors.
"There are a good number of highly unsuitable and in some cases downright pornographic materials being peddled in our schools.
"We want it to be made mandatory for schools to publish a list of the resources that they are using on their school websites and for certain explicit and graphic materials to blacklisted.
"We also want a new schools safeguarding committee set up regarding RSE only, with a protected whistleblowing status."