Critics have called Tes, one of the UK’s biggest lesson plan providers, a ‘Wild West Marketplace’, after inappropriate sex education materials were made available.

Tes, a weekly publication aimed at education professionals, removed the materials after the Times raised concern.

The materials uploaded by Cre8tive Resources included exercises encouraging children as young as 11 to consider high risk and low risk activities associated with intimate relationships and were easily downloadable by teachers.

Speaking to MailOnline, Tes stated: “The resources that were brought to our attention were swiftly removed and are under investigation. Our robust 'take down policy’ allows us to tackle anything of concern …”

“It is important to note that Tes provides a resources platform to facilitate the sharing of content created by teachers for teachers … The platform is open to all who wish to share classroom teaching resources under the terms of the Tes author code.”

Miriam Cates, an MP who has been campaigning for a review of sex education in schools, told the Times: “It is disappointing that these resources appear on the Tes website and is further evidence of the unregulated Wild West of relationships and sex education teaching materials.”

The Family Education Trust also stated:

“The Department for Education guidelines call for relationship and sex education to be 'sensitive, age-appropriate, developmentally appropriate and delivered with reference to the law … resources like these put vulnerable children and young people at risk by encouraging a casual attitude to sex.”