Religious campaigners have hit out at “explicit” sex education resources they claim are inappropriate for primary school children.

A report by the Christian Institute claims materials available to schools contain unsuitable language and information for pupils.

Many of these resources are re-commended for teaching by local authorities, it says, and aimed at children as young as five.

The report says one resource, a book called How Did I Begin? by Mick Manning and Brita Granstrom, is recommended for children aged five and up.

Another book, Where Did I Come From? by Peter Mayle, shows cartoon pictures of nude people and descriptions of their bodies.

This book, the report claims, is recommended by two councils for children aged seven and older.

The report highlights a primary school sex and relationships education pack, recommended by a number of authorities. It claims the pack includes a glossary giving de-finitions for terms including “anal intercourse”, “bisexual” and “clitoris”.

A book called Let’s Talk About Sex, by Robie H. Harris, which includes a chapter on heterosex-uality and homosexuality called “Straight and Gay”, is also highlighted in the report. The book is aimed at pupils aged seven plus.

The institute’s document highlights a number of other books and resources which include definitions for terms such as “incest”, “lesbian”, “oral sex” and “orgasm”, as well as discussing issues like masturbation.

The report’s introduction says: “At a time when there is growing alarm at the sexualisation of childhood, using sexually explicit resources in schools can surely only make things much worse.

“If sex education is made compulsory for primary schools, the publications highlighted in this report are the kind of materials that will be used with young children.

At the moment, primary and secondary schools have to teach pupils age-appropriate lessons about the biology of sex in science.