Members of the National Union of Teachers (NUT) have called for children as young as two be taught “age-appropriate” content on LGBT matters.

The calls come after the government announced that all children from the age of four will be taught about safe and healthy relationships, while sex education will become compulsory for all secondary school pupils.

However teachers at the NUT’s conference say current provisions for sex and relationships education (SRE) had a “lack of policies which promote LGBT+ within schools”.

They added that this can have a “significant negative impact upon the health and well-being of students”.

Teachers at the conference, in Cardiff, voted to back a motion that said they would “campaign to ensure a comprehensive age-appropriate content including promotion of LGBT+ matters for all schools from nursery throughout all phases of state education”.

Annette Pryce, a member of the NUT’s executive, said the government’s current plans are “not inclusive”.

She told the conference: “Those generations of young LGBT+ people who have been failed by the system are still not told explicitly in the law that their lives are important too,” Ms Pryce said.

“The NUT… needs to ensure that SRE is inclusive to LGBT young people now and forever.”

Kiri Tunks, a teacher in East London and the NUT’s vice president said: “This is a dangerous loophole that will leave many young people ignorant and vulnerable so while relationships will be taught in primary school, sex won’t.

“The need for fully funded and inclusive SRE is huge. Let’s continue campaigning for proper inclusive sex education in all our schools for all our children.”

Members also expressed concerns that a “right wing, religious lobby” would water down government plans.

In March MPs passed a government amendment to make sex and relationship education mandatory.

Education Secretary Justine Greening drew up plans that she would act to make SRE mandatory in all schools, after pressure on the issue from sexual health and children’s campaign groups.

The plans do not include a commitment to LGBT-inclusivity, but LGBT charity Stonewall says it will be “working with the Government to ensure [LGBT issues] are reflected in updated guidance for schools”.

Her plans were given the green light by MPs, with the amendment to the Children and Social Work bill passing with near-unanimous support.

The bill will get royal assent later this year.

Schools must also make public a “statements of policy in relation to the education to be provided”.

Stonewall Chief Executive Ruth Hunt, said: “This is a huge step forward and a fantastic opportunity to improve inclusion and acceptance in education.

“Currently over half of secondary school students say they never have any discussion of LGBT relationships in their lessons, and over half of lesbian, gay, bi and trans young people are bullied in our schools because of their sexual orientation or gender identity. That is unacceptable. By mandating all schools to provide good quality, age-appropriate relationships and sex education the Government has paved the way to change that situation.

“This should mean that all schools provide the space to discuss LGBT relationships and the issues LGBT people face, enabling more lesbian, gay, bi and trans young people to feel accepted in their school environment.

“We look forward to working with the Government on updating the guidance for schools to ensure that this measure helps to transform the experience of LGBT young people in all schools.”