The head of Ofsted has called on campaigners to halt protests outside the gates of schools that teach pupils about LGBT issues, claiming it “serves no one well to intimidate teachers”.

Chief inspector Amanda Spielman used her speech at the Muslim Teachers’ Association’s  40th anniversary yesterday to say the protests make a “difficult situation worse, while setting a terrible example for the children”.

“It is children’s voices that always get lost when adults stop talking and start shouting,” she added.

Protests over relationships and sex education have been taking place around the country, with many parents and religious groups citing concern about the teaching of LGBT issues and homophobia in schools.

Parkfield Community School in Birmingham has been the target of several protests, with parents withdrawing their children from school over the teaching of its ‘No Outsiders’ programme. The school has now suspended the teaching of the programme until a resolution can be reached with the wider community.

Ofsted has given its support to the lessons at Parkfield, after ruling that the teaching was “age appropriate”.

Spielman said events at Parkfield were an example of “where dialogue is essential” in dealing with “issues and tensions when they arise”.

“I understand the strength of feeling in that community. But it serves no one well to intimidate teachers and start protesting outside the school gates.”

Instead, Spielman called for “calm discussions in order to find a sensible middle ground – one that means children are prepared for life in a diverse, modern, progressive country like ours, but it’s done in a sensitive and careful manner”.

Many schools already teach some form of LGBT education. In Manchester, template letters opposing sex and LGBT education have been handed out at school gates, while around 250 parents have joined a Whatsapp group opposing the lessons. The Manchester Evening News reported some of the messages sent are homophobic nature, including discussing the sexuality of teachers.

On Wednesday, MPs voted in favour of reforms to make relationships and health education compulsory in all schools, and sex education mandatory in all secondaries, from 2020. The reforms still need approval from the House of Lords.