A group of prominent NGOs and MPs have signed a letter to Michael Gove stating that parents should be at the heart of sex education.
The letter also calls on him to resist any pressure to alter the content of Sex and Relationships Education (SRE) guidelines.
Antonia Tully, of the Society for the Protection of Unborn Children's 'Safe at School' campaign said: "There are over 90 references to the importance of parents in the current guidelines which, as we say in the letter to Mr Gove, is an important recognition that parents matter. Those lobbying to change the guidelines have no intention of involving parents in any re-drafting.
"We keep hearing that so-called 'experts' are needed to develop and deliver sex education in schools. We are saying that parents are the experts. We look forward to a response from Mr Gove."
The letter states that parents "must be affirmed in their role as the main educators of their children in matters of sex and relationships".
"Schools can support them in this role, but should not take over from parents," it reads.
"Parents also have a crucial role to play in protecting their children from the influence of pornography via the widespread access to the internet available to children and young people. Most parents would prefer their children not to watch pornography. Yet the ideas being promoted by the Sex Education Forum on teaching pornography in the classroom are focussed on helping pupils to explore pornography, not warning them against it."
The group were praising of some recent developments, welcoming changes to the new National Curriculum for science in primary schools that keeps information about human sexual reproduction out of science lessons.
"We are also pleased that personal, social and health education was not made a compulsory school subject in the new National Curriculum," they said.
However, the letter goes on to express concern about threats to the right of parents to allow their children to opt out of sex education classes.
"There is absolutely no evidence that removing this right would have any adverse impact on the wellbeing of children and we urge you to maintain this important right for parents," they said.
The letter also argues that there is no benefit to further expanding the sex education curriculum.
"There is no evidence that graphic sex education in primary schools lowers teenage pregnancies. A number of robust studies show that access to abortion and contraception, widely promoted in secondary schools, has not reduced under-18 conceptions" although no references or details of these studies are provided," it reads.
Signatories of the letter include Tory MP David Davis, Norman Wells of the Family Education Trust, Professor David Paton of Nottingham University Business School and Dr Lisa Nolland, of the Lords and Commons Family and Child Protection Group.
The letter has been sent in opposition to the Wonder Women campaign lead by The Daily Telegraph, which is advocating for changes to current sex education guidelines to reflect changes to childhood and adolescent sexual development in the digital world.
The Daily Telegraph's petition's on Change.org points out that current SRE guidelines "contain no reference to the internet mobile technology or online bullying".
The Telegraph web page dedicated to the campaign states: "We are calling for David Cameron to convene a group of experts to update the sex and relationships teaching material to reflect the digital era we live in.
"This official guidance, which teachers rely on, was published in 2000 … and has not been updated since, predating the internet as we know it."
The Daily Telegraph's petition has so far generated over 52,000 signatures.
It was drafted by Yas Necati, a lead figure in the Campaign4Consentasking the government to make teaching about sexual assault, consensual sexual contact, and healthy relationships a compulsory part of the national Sex Education curriculum.
Responding to the letter to Gove, a Telegraph Media Group spokesperson said: "The Daily Telegraph's Better Sex Education campaign is supported by and works closely with parenting and family groups such as Mumsnet, Parent to Parent, Netmums, Family Lives and The Mothers' Union as well as schools, teachers and young people, in a bid to bring sex and relationships education into the 21st century."