Three in ten teachers deliver relationships and sex education classes with no training, a survey has found.

The survey of 240 teachers by the Sex Education Forum and PSHE Association found that 29 per cent had received no training on RSE. And 38 per cent said that the training they did receive was inadequate.

Teaching RSE constitutes a small proportion of teachers’ roles, with only 16 per cent saying they spent more than a fifth of their time teaching it.

Topics that teachers said they felt least confident teaching in secondary schools included contraception, pregnancy options, sexually transmitted illnesses, accessing sexual health services and providing guidance on sexually explicit information online.

Some 20 per cent of respondents said they lacked confidence in adapting teaching to meet the needs of children with special educational needs and disability (SEND), while 21 per cent said they lacked confidence in making the curriculum LGBT (lesbian, gay, bisexual and transgender) inclusive.

The results have been published as the Sex Education Forum and PSHE Association launched a “joint roadmap” to statutory RSE, with the support of five unions: the NEU, the NAHT heads’ union, Voice, the Association of School and College Leaders and Unison.

Lucy Emmerson, director of the Sex Education Forum, said: “The vital ingredient in effective RSE is the people who teach it. The guidance on what the statutory curriculum will cover is well underway, but what training and support will be available to schools remains to be seen.

Commenting on the roadmap, Jonathan Baggaley, chief executive of the PSHE Association, said: “We hope that schools will find the guidance, practical tools and steps valuable.”