The NAHT said it had shared examples of some of the “damaging experiences” it said its members had faced with Education Secretary Lucy Powell.
Powell told LBC earlier this month that she took head teacher wellbeing “incredibly seriously” and that the system of accountability needed to be “supportive and understanding.
“I’ll continue the work that I do with head teachers, head teacher representatives and others to make sure that we get this Ofsted framework, but also the culture and the whole regime, right,” she said.
The NAHT said the results of a recent survey of its members suggested that the majority who responded felt that inspections had worsened in the past 12 months.
The union is now calling for inspections to pause to allow for a “fundamental review of how inspection works”, drawing on examples from other nations.
In Wales, the inspectorate Estyn has removed judgements such as “excellent” and “good” from its reports, instead summarising findings by highlighting a school’s strengths and areas for improvement.
Northern Ireland’s Education and Training Inspectorate (ETI) also uses narrative reports without grades.
Scotland’s His Majesty’s Inspectorate of Education (HIME) does use grades, but there has been a recent consultation on their use.
NAHT general secretary Paul Whiteman said: “The clear theme emerging across all the feedback we have received is that this Ofsted framework is even more stressful than the one that preceded it.
“It poses a real and present danger to the well-being and mental health of school leaders and teachers, possibly even a risk to life.”
He said he welcomed the new education secretary’s focus on teacher wellbeing, adding: “Really fundamental changes to inspection are needed, and we stand ready to work with the new government to achieve that.”
Ofsted said it had worked closely with teaching unions over the past three years to deliver significant reforms and reduce unnecessary pressure on teachers.
“Ofsted exists to raise standards for children and to provide clear reporting to parents,” a spokesperson said.
“We will continue to engage closely with trades unions – but we will also continue to grade schools.”
