School leaders are being pressurised “to the point of destruction”, the head of a teaching union has said, as he put the education establishment “on notice”.

During a speech to the union’s annual conference in Belfast, Paul Whiteman, the general secretary of the National Association of Head Teachers (NAHT), outlined his criticisms of Ofsted, the schools watchdog for England. .

The two-day gathering, which began on Friday afternoon, is the first of its kind since Ofsted introduced a “Nando’s-style” scorecard inspection framework in November – a move vigorously opposed by a number of teaching unions.

Whiteman told delegates: “Ofsted does not raise standards, nor does it serve children”, and he pushed back against claims that “anyone who wants a different approach to inspection wants to lower the bar”.

After the high court dismissed a legal challenge to the new inspection regime, the NAHT considered taking industrial action but has since rowed back in response to talks with Ofsted and the Department for Education (DfE). These discussions resulted in further measures, including the creation of an independent advisory group to monitor the impact of the changes on headteachers’ mental health and wellbeing.

In 2023, the headteacher Ruth Perry killed herself after Ofsted inspectors planned to downgrade her primary school from “outstanding” status to “inadequate”. An inquest found that the inspection was a contributing factor to Perry’s death and her family led a campaign that succeeded in ending single-word Ofsted reports.

Whiteman said : “Inspection should not be about pressurising dedicated professionals to the point of destruction. I am angry – yes, mad as hell – that Ofsted, the government and the judiciary see fit to allow lives to be left at unnecessary risk right now.

“I say the education establishment is on notice. On notice that these risks are entirely foreseeable and avoidable. The responsibility for further harm or, God forbid, tragedy, is yours and yours alone.”

Under the scorecard system, schools no longer receive an overall grade but are instead judged across six different inspection areas with a five-point grading scale.

While Whiteman cautioned headteachers against the “reductive nature of a two-day snapshot of your school”, the NAHT leader also praised recent government policy, such as the expansion of free school meals, removal of the two-child benefit cap and the setting up of Best Start family hubs.

On the topic of reforms of provision for special educational needs and disabilities (Send), Whiteman raised the issue of “proper funding” for the measures outlined in a recent white paper, which is under consultation before a possible bill to be included in the king’s speech during the next state opening of parliament. The DfE has said it will allocate £4bn to overhaul Send provision in England.

Whiteman addressed the conference on the “politics of hate and division at work across the world” and the role that teaching staff could play in challenging people who aimed to increase societal divisions.

“That is why they seek to deny the problems you encounter every day and fail to acknowledge your success,” he said. “By casting you as the enemy, with a continuing deficit narrative, they will routinely and deliberately seek to erode the respect and confidence of parents and communities.”

• In the UK and Ireland, Samaritans can be contacted on freephone 116 123, or email jo@samaritans.org or jo@samaritans.ie. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at www.befrienders.org.