A group of school representatives in Kent have written to the prime minister calling for a reform of Ofsted inspections.
It follows the death of Ruth Perry, a head teacher in Reading who took her own life while waiting for a report.
The letter said the current inspection regime is having a "detrimental impact" on the mental health of school staff.
An Ofsted spokesperson said it was willing to have constructive discussions about the issues.
The letter was from Medway Educational Leaders Association (MELA) and Kent Association of Headteachers, which represent more than 900 schools.
It said the current inspectorate was "not fit for purpose" and has had a "negative impact on the education system".
