MPs in Westminster are to hear an urgent call to re-think sex education ahead of the roll-out this September of the Government's new Relationship and Sex Education (RSE) curriculum.
The Rev Lynda Rose, chief executive of Voice for Justice, is leading a briefing in the Houses of Parliament on Wednesday night in which she will call for an "urgent reassessment" of current sex education policy.
She will propose a ban on the promotion of gender fluidity to young children, which she said was "deeply confusing" and "destabilising to their development".
Parliamentarians will also be urged to closely scrutinise compliance with RSE regulations to ensure that teaching is age-appropriate and conducted with proper regard to the religious background of pupils and their families.
"In view of epidemic level rates of STI amongst teenagers, we are calling for urgent reassessment of sex education that will alert children and young people to the dangers of STIs, some of which are untreatable, and some of which are increasingly antibiotic resistant," she said.
"In particular, we want young people to understand that, despite what's claimed, condoms will not always 'keep them safe'. If they don't know the dangers, they can't possibly make informed decisions."
She continued: "In light of all this, we are saying that as a society we need to decide whether our priority is child welfare and protection, or the promotion of ideological values that justify adult behaviours.
"Children need protecting, and there is much in the Regulations that is good - but there are also elements that provoke concern, and we want the Government to reassess its policies so that child welfare is prioritised."
Rev Rose is Joint Convenor of the Lords and Commons Family and Child Protection Group with Sir Jeffrey Donaldson, the DUP's most senior MP.
The meeting tonight has been criticised by some MPs. Angela Rayner, shadow education secretary, told The Times: "It's extremely concerning that this event is taking place in parliament. Relationships and sex education is of crucial importance, especially for LGBT+ pupils."
Rev Rose defended the meeting and opposition to the RSE curriculum.
"All our assessments are based on official Government data and medical reports relating to child welfare, as evidenced for example by official figures for epidemic level STI infections amongst teenagers, increasing rates of child-on-child sex abuse - some involving children as young as 5 - and a 4,500% increase in child referrals for gender reassignment over the last decade," she said.
"As a society we have to decide whether our priority is child welfare and protection, or the ideological promotion of 'new' values that justify adult behavioural choices."