Ofsted chief inspector Amanda Spielman has strongly criticised the government for a lack of leadership over the protests about LGBT teaching in primary schools.
She said teachers and pupils were forced to listen to a "diatribe blasting though megaphones" outside their school, but said there was no swift condemnation of this from government.
Ms Spielman said that, in contrast, Ofsted had spoken up for these schools and would continue to do so.
Court ruling: LGBT protest permanently banned
Schools in Birmingham faced major protests outside their gates over teaching children about LGBT families.
Anderton Park Primary and its head Sarah Hewitt-Clarkson had to seek an injunction in court to move these protests away from the site after weeks of noisy demonstrations just metres away from the school.
Speaking at the launch of Ofsted's annual report today, Ms Spielman said: "The subject of [protesters] anger was relationships education in primary school – which generally amounts to telling children that there are different types of families, some with a mum and a dad, some with just one parent, some with only grandparents and some with two mums or two dads."
Ofsted: LGBT protests 'intolerable'
Ms Spielman said protesters constructed "a depressing tissue of exaggeration, outrage and, sometimes, lies" about what was being taught in these schools.
She added: "The children, as well as teachers, had to walk into school past placard-waving protesters and then listen to diatribe blasting through megaphones outside. It was, quite simply, intolerable.
"And yet, there was no swift condemnation from government and remarkably little from other local and national political leaders. The powerful voices that should have supported the children and the school were largely muted. Headteachers spoke of being isolated.
"Where leadership was desperately needed, it was lacking.
"So we spoke out. We backed the headteachers under fire and we said unequivocally that children should learn about different kinds of family. And I will keep us doing what we can to get people to face and talk about the difficult things."
The Department for Education has been approached for a comment.
The previous education secretary, Damian Hinds, said that parents should have no veto over what is taught in relationship lessons.
The government is introducing compulsory relationships education for primary schools and compulsory relationships and sex education for secondary schools from September this year.
Ms Spielman was launching her third annual report as Ofsted's chief inspector.