Christian parents have lodged a formal complaint with a south London school after a teacher was allegedly recorded warning pupils that they would be "dealt with severely" if they rejected LGBT ideology.

The incident is reported to have taken place at Stationers' Crown Woods Academy after a Muslim boy objected to watching a video affirming children coming out as gay, lesbian or bisexual.

In the recording, a man reported to be a teacher at the school can be heard saying, "You don't have a choice whether or not you learn about LGBTQ+ in this school.

"It's one of our values. They're British values, and if you refuse to do it, that will be dealt with severely."

The Christian parents of a boy at the school, who wish to remain anonymous, claim that their right to raise their son in accordance with their "deeply held Christian beliefs" have been infringed upon. 

They are being supported by the Christian Legal Centre (CLC) in their complaint against the school.

In a letter to the school, the parents allege that the teacher "abused his position of trust in using his platform as a teacher to threaten and shame pupils, none of whom apart from one student, made any comments about LGBT education".

They also said that they were "concerned about the focus of the school and the manner in which it has approached LGBT issues".

"My family and I are Christians. We love our proverbial neighbour as we are called upon by our faith and Scripture to do so. Nevertheless, also in accordance with our faith and Scripture, we do not accept same-sex relationships or relations as being prescribed by God," the letter states.

"We accept that we live in modern Britain, but it is highly upsetting to be told that our beliefs do not accord to British values. It is equally upsetting that my son was shamed in this manner despite not having made any negative comments about anyone in the LGBT community."

It continues: "No statutory definition of British values exists ... the school owes a statutory duty to ensure that the education it delivers respects the manner in which parents wish to raise their children in accordance with their own religious convictions."

CLC chief executive Andrea Williams said: "It's rare to gain a window into the world of a UK school classroom. Here we have exposed at first hand the language and actions of a teacher promoting LGBT ideology.

"Where is 'diversity' and 'tolerance' here? We have only a monoculture which requires approval and promotion of the "Progress" flag, or "Pride" flag, or transgender flag. There is no choice or freedom to disagree.

"The teacher in the recording is so brazen he actually tells children that if they come from a family with beliefs opposed or contrary to LGBT ideology, to go home and challenge their parents and convert them to his beliefs.

"Thousands of children in primary and secondary schools are being forced to absorb extreme LGBT ideology without their parents' knowledge.

"We will stand with this family as they take forward the complaint against the school."

In a statement responding to the claims, Leigh Academies Trust, which operates Stationers' Crown Woods Academy, said an investigation had been launched into the recording and the findings would be reported to parents in due course.

"From the preliminary stage of our investigation we have identified that the recording was made during an incident where a second teacher was called into the class to address a number of students who were not engaging appropriately with the lesson," the Trust said.

"Having analysed a full transcript of the recording we are satisfied at this stage that the teacher's conduct during the lesson did not breach any statutory guidance related to the teaching of relationships in school, nor did it breach any guidance around the safeguarding of students or the Equality Act.

"We acknowledge that some families may have concerns or differing views on these topics, which is why we encourage open dialogue between parents and their children as well as with parents and the academy so that any concerns can be explored. Our aim is to work collaboratively with families to ensure that all students receive an education that meets their needs while upholding our commitment to promoting inclusivity.

"We take the wellbeing and safety of all students and staff seriously and it is clear that this covert recording has caused distress and harassment within our school community to the extent that we have had to report ongoing homophobic harassment to the police."