The head of a school trust embroiled in a row over classes about LGBT rights says staff have been left "distraught".
The No Outsiders programme at Parkfield Community School in Birmingham has been paused after protests by parents.
Hazel Pulley, chief executive officer of the trust which runs the school, said some staff had lost weight and were not sleeping.
She added the situation had been the most "challenging" she has seen in 27 years in education.
There have been protests outside the school in Alum Rock over No Outsiders, with some parents claiming the lessons were age-inappropriate and incompatible with Islam.
Ms Pulley, of Excelsior Multi-Academy Trust, confirmed its lessons have been temporarily stopped to allow for discussions with parents.
The Leigh Trust has also said it would be halting lessons at four of its schools until reaching an agreement with parents.
"The impact on staff has been tremendous," Ms Pulley said.
"The reason is because of the breakdown in the relation of trust which we have had for so long."
She said the No Outsiders lessons use a book featuring two mothers and their child, and depicts them doing "normal things".
The idea is to show children how "all families are different".
"We are not teaching children about same sex couples in the sense of sexual relationships, what we do teach our children is that there are different families and that there are families with two mummies, two daddies."
Ms Pulley said: "During this period where we said we are putting No Outsiders on stop, we have made sure that in our curriculum and in our assemblies we do not mention the LGBT agenda, because that is the only way we felt parents could come into the room and start talking to us.
"We moved what we thought was the issue to one side but we can only do that for so long or otherwise, quite rightly, we will be seen as being discriminatory to one of the protected characteristics."
She said the programme can sit "harmoniously" with Islam, adding: "In school they need to be educated to the laws of the land and at home they can follow their religion and that is fine; the two sit together."
Ofsted has deemed the lessons "age-appropriate".
On BBC Radio 4, its former chief inspector Sir Michael Wilshaw called for the classes to be reinstated, but said it is important parents are consulted.
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